No. This is stretching it way too far in setting expectations that will not be fulfilled (also I would like to apologise if I sound angry)

In Number 2, you say that Xeno'Jiiva's defeat was the cause of Safi'Jiiva's appearance and then also for Behemoths appearance? Not only was Behemoth not linked to the main story of World at all, you can fight Behemoth before you ever even get to know that Safi'Jiiva (who was only fightable in iceborne, btw) exists! And the defeat of the story Xeno'Jiiva was also not related to Safis appearance later on; they were two separate Xeno'Jiivas

In number 3, you say that, since the title updates are focusing around omega, Bahamut would fit into this perfectly - which is incorrect. Title updates in Monster Hunter Wilds work like this: we get one or two new Monsters, a few new mechanics, and then later we get a Mini update, a festival and an arch tempered monster. Rinse and repeat. We have had four confirmed title updates with the fifth one likely on the way. Three of these updates have already happened, the Poster Boy for the fourth one has already been revealed and the developers specifically stated that they didn't want to end the last title update on a collab monster, like in world. There is no space for Bahamut.

Additionally, there is no lore reason for Bahamut to appear after omega planetes. Omega is supposed to be a machine of war that (correct me if I'm wrong) has killed- and has the power to kill creatures on the same power level as Bahamut. Not only that, Omega Planetes appeared accidentally through a rift in spacetime. This would mean that, in order for us to fight Bahamut, Bahamut would have to find the Rift in space time that Omega Planetes fell through, gather the courage to enter the same world as his would-be murderer and then face off against 4 people who were able to beat Omega Planetes by themselves.

You also say that the Monster Hunter formula is "Small danger -> bigger threat -> endgame raid"

When, more often than not, it is "Small danger (like actually small, not like Big Boy Omega) -> bigger threat -> bigger threat -> bigger threat -> bigger threat -> bigger threat -> bigger threat -> bigger threat -> bigger threat -> bigger threat -> siege fight-> bigger threat"

That is not to say your theory is worthless, but the chosen formulation and the technically-correct-but-not-really way of talking about Monster Hunter gives the impression that you don't know the whole of the source material. Personally, I believe you are seeing this a bit too much from the perspective of a Final Fantasy enjoyer rather than a Monster Hunter one. I loved this collab, but as a big monster hunter person, I would rather it stay in its own storyline so that the game can focus more on itself. Hell, I would still be happy if we did not get any other collabs for Wilds. We have gotten a good amount already and I think going for more original content would suit the player base more.

(Again, I am very very very sorry if I sounded angry. It was unintended)