There is a lot in what you write, I think, but I suggest there may also be the spectre of the PR team in the background, which may account for the changes you perceive.
I have read about 3 sets of couples in Entertainment over the past 3 years, where PR may or may not have been involved.
1) the Tom Hiddlestone/Taylor Swift love affair in 2016, which may or may not have been PR inspired. There certainly seems to have been PR involvement at times. e.g. the beach shots, where Hiddlestone wore a vest on which was inscribed "I
TS"
2) the Ant McPartlin travails of the past year including the car crash and the divorce, where PR involvement is often suspected
3) the recent troubles of Kevin from Grimsby and Stacey Dooley, where again there is reference to PR teams for both involved.
I don't know if Joe uses an agent but Margravine presumably would be it, if he does. Dianne surely has an agent, according to her Twitter details.
SCD would also have its own PR team
Dianne is mainstream media and understands the importance of public appearances and smiling for the camera. It is meat and drink for mainstream entertainers, and while much can be and is written about the symbiotic relationship between the entertainment world and the mainstream media, there can be no doubt it exists and that PR teams are useful for oiling the wheels. I would say it is the price of entertainment success, that you must be prepared for intrusion from paps etc, like it or not. That is where PR management comes in.
Looking at Joe, I would say that up until the last month, his handling of the mainstream media has been abject.
1) in a vid before Xmas, he lambasts the media for knocking on his grandmother's door, and complains about being followed on the motorway by a pap,. while driving a Aston martin with James Bond plates. I felt Joe;s peroration was authentic but naive. You don't stop the paps by asking them to stop. This suggested to me that either he had no PR team, or was ignoring them
2) Joes makes a concession to the media and posts his image before Xmas with "I have may not have won the glitterball but.." I always thought this was his idea, but maybe not,.
3) Fairly soon after Dianne's return from Australia, Joe goes on YT again, and once again lambasts the media, this time for running engagement stories about Dianne and himself. I felt the way he handled the aspect about Dianne was ppor.
4) The Pro tour started in mid January. You would have to be really naive to think there would be no media. At the every least, the Beeb PR team would arrange photo ops.So what occurred?
4.1 Throughout the tour, Joe continued to glower at the camera when papped. It made you wonder if he was unhappy with Dianne.
4.2 There was the night of the NATV awards when SCD won, and many Pros including Dianne were present, as well Celebs on tour like Dr Ranj and Graham. Joe chose to keep what he claimed was a longstanding commitment for dinner with the Buttercreams,.
4.3 There was the occasion when a camera caught Joe and Dianne returning to the hotel one evening. The reporter called out, Joe half-turned, saw who it was and turned back and marched resolutely into the hotel. Dianne smiled at the reporter, and halted momentarily, but then seeing Joe was gone, she turned and hurried after him.
4.4 The Sun started a mischievous story, eagerly seized by other media like the Mail, that Joe and Dianne were upsetting the tour, by constant PDAs. I suspect this story may have been false with its unattributable sources, but it seemed particularly odd, because there had been no real PDAs from Joe at that point on the YT vids.
At the ned of the tour, there is a YT vid by Joe, in which he jokes about who he might vote for, if a Youtuber is in the the next SCD season, going up against Dianne and her partner. Dianne off camera, jokingly but curtly tells him 'Me of course' and then adds "You better edit that out of the video'
The ensuing
Here Come the Girls tour seems by general concensus to have been underpromoted. The IG traffic been Joe and Dianne on the other hand increased in PDAs on both sides. Was this conscious self-promotion by the pair? Or had a member of one their PR teams stepped in by then and effectively said that Joe had to man up with regard to their relationship and the MSM? Or has Dianne said words to the effect that if
In the Pan is aimed at promoting them both, he has to change his attitude about mainstream publicity? It's a bit of both, I think.
Feel fre to demolish this. I cannot prove a lot of what is written, but it seems to me that if Joe wants mainstream media success, he has to accept a degree of press intrusion and so, the hidden hand of a PR team may now be around. For certain, Joe cannot continue tto act in a high-handed way with the press if he wants publicity, unless and until he has a more certain position in the mainstream media world. Giving podcast interviews will not project him in the way that the press can, if they are steered in the right way.
tl:dr the dynamics of the couple's relationship may have changed the way Joe behaves to Dianne online, but I suspect there is also a guiding media-friendly PR hand at work as well.
) video where he was a 'paparazzi' you can see Joe walk out of the hotel with a guy and Alfie says 'Joe with his agent'