I don't think Yaz and Ash will ever come back because their youtube career was a vanity project, whereas Magical Day is their livelihood. Tbh, if they did come back with a genuine apology I think that would sit OK with me.
Knappily have come back because after 6 months I'm pretty sure you become demonitised and it's not as easy as just "coming back to Youtube". I'm fairly sure they've taken a break to ramp up engagement and I am (no so) surprised they're back to pushing their kiddies faces right back out there again. The Vlogging world has changed so much IMO in these past 6 months and there's so many others doing it now (for better or worse) DisneyHannah, Dalimore etc.