The funny thing about big conspiracy theories is that they start with something that is really murky and suspicious - and with dubious supporting facts - and grow it to craziness anytime involving more and more people to make things make sense in their heads.
So, regarding the children:
1. There is absolutely no public evidence that they do not exist. There is absolutely no public evidence that they were born via surrogate. There is absolutely no public evidence that the ILBW was never pregnant;
2. There is a weird baby bump that seemed to move around - yes. Are there other reasons for the weird bump besides she not being pregnant? Yes: she was obviously there for the attention, so she could have wanted to have a bigger bump than the one she had, for instance (she is crazy stupid for that, and would justify all the coats flipping - she knew the bump was what photographers were after); some of the footage could also reveal bad pregnancy underwear - and because she was dressing tighter clothes (she really, really wanted us to see the bump) they would make the weird moments;
3. Is it all very murky around Archie's birth? Yes. Why would she skip an obvious Diana moment of having photographs taken on the stairs of maternity? The birth certificate that was not signed? Hazno words on the child presentation. Yes, all these are murky. But we also know that TW is vain and even several days after the birth she was all swollen, even her face was different. Maybe she had a C-Section but wanted to one day sell the birth story of giving birth in a pool with a doula. Maybe the child was born much earlier and they wanted to exert control over the narrative and over the Royals. I would be shocked if HLMTQ and the then DoE had their picture taken with a doll. Is there any evidence of all I was saying? No. Is there any public evidence Archie doesn't exist? No.
4. Is it all very murky around Lilibeth's birth? Yes. First the dates don't add up to the sad story of the miscarriage. Then there seem to be no records - although there is a Diana Mountbatten Windsor born around these dates. I never understood why they wouldn't name the girl Diana, given the obsession, and maybe they did, but then used the Lilibet to appeal to TLQ's heart and ask for money. How was she born, who gave birth to her - I have no access to information on that - as no one on this forum or on Youtube.
5. If the children are not true, do I believe TRF is hiding it? I lack evidence. I think they probably don't know. Even if Secret Services could have more information, I highly doubt that they could do a big reveal without breaking some rules and laws. I highly doubt the Crown has the power to stop journalists around to world to sop publishing any evidences they have on this: the thing is, there are no evidences. There is speculation, a lot of it, but a tremendous lack of factual evidence.
Knowing what I know of the Harkles, we know the ILBW is attention seeking and until any of this is proved (weather the children exist or not) she has people talking about them, which is always her ultimate goal. Hazno is disturbed and I wouldn't be shocked if he was obsessed with hiding the children from the Media and criticising his brother every time the Wales' children make any appearance. If the children do exist, I expect the ILBW to start monetising them immediately after the divorce. If they don't, I am here for the drama.