True, and I agree that designing a new archetype is easier, but a big part of the well-loved BYOW is the Patron + Pact Boon aspect. They will, IMO, have to weigh those two things against each other.
I do see either the Hexblade or the Bladelock going the way of the dodo. It will be one or the other, but likely not both. Either the Bladelock will steal the Hexblade's soul or the Hexblade will steal the Bladelock's soul.
Pretty much. I have been considering running a game set in Iomandra, though I'm not sure if I would use D&D 5e or some other system (e.g., WWN, ICRPG, etc.) for that purpose.
In the end that I think that cognitive dissonance about these issue will be what wins and what WotC is counting on. At the end of the day, the reality of D&D as a "lifestyle brand" is that people are willing to put up with and rationalize changes they dislike for the sake of playing D&D.