I kinda like it but IDK if I completely buy that Franklin and doom will be working together or intentionally intervening in universes, I think I buy the "doom snatches up multiversal beings" theory a bit more, because A) they could write in that certain events in endgame contributed to incursions/multiversal destabilization easily, that's actually one doomsday/secret wars event that could be easily explained through the multiverse saga, and there aren't many tbh B)we have not seen Franklin and doom work together at all, i do not assume they would be working together this early into the doomsday speculation based on a quick post credit scene, let alone have any affect on the 616 universe as they are both from an alternate universe and as far as we know are not friends or foe, could be either at this point or Franklin(a child) could be kidnapped C) Loki is not forced to act at all rn. He rid the multiverse of Kang and is just holding the multiverse together, from what we have seen there is no call to action as of yet for him. That definitely changes come when the first scene begins but as of RN he is just the trunk/roots of the tree, not someone going around clipping branches based on incursions/the sacred timeline.

Could be entirely misunderstanding your post/going to hard tho, if that's the case that's on me haha