The Sorcerer and the Warlock should have been one class to begin with, every "power source" that works for the Warlock would also work for the Sorcerer. And after the Divine Soul/Celestial Pact planted their heels into the Clerics Foot, there is no reason to worry about stepping on toes now.
As for me: I want a Plant Druid, Archer Paladin, Thug (Str based) Rogue, and a Wizard subclass that not-so-smart people can play to feel smart.
I’ve rarley disagreed more with a statement about DnD. IMO, while most of their “power sources” could easily be shared (Dragon is patron, fiendish bloodline, etc) the similarity literally ends there, and isn’t close to enough to combine into a single class.
I like your subclass ideas, though.
For me, I want:
Acrobat rogue (already being done, tho I wish he would include being able to Sneak Attack with a quarter staff or spear into it)
Shadowfel related patron (or even just bring back the Raven Queen patron) for Warlock
Primal Spirits/Ancients Warlock Patron (gets some Druid/ranger spells, ability to call forth some spirits, etc)
Sohei Monk (another weapon focused Monk subclass, but this one can use polearms, and isn’t super boring.
Bard College of The Fey Beast Tamer (chain pact bard meets beast master bard. Cast Find Familiar with some special options like Winter Wolf pup, Owlbear cub, Blink Dog Pup, Displacer Beast cub, etc, use it at 2nd or 4th level to go from cub to adolescent to adult version, with some abilities to spend Bardic Inspiration to do cool things through the pet, and/or burn spell slots to activate useful auras centered on the pet. And the pet gains proficiency in Performance.