That is bizarre behavior. I can see "well, we really need a cleric..." (I can't un-see it, even after all these years), but heck, play what you want. These are AL DMs?
FWIW, I wouldn't have any trouble with a Sorcerer having a different spell list than normal - I'd probably draw the line at 'Name' spells, and might approach it as "tell me your concept, and I'll give you your list of known spells" (which'd be more like slowly discovering an innate power, anyway, since you're not literally going through a spell syllabus, deciding what you want to 'learn' like a wizard) if that sounded like fun. Heck, I'd want to throw in the odd original spell.
Familiar? Heck, I have a Thief in my 4e campaign who has a familiar (mechanically it works like one), because a critter just decided it liked him....
I think you're just unusually unlucky with your pool of DMs.
How do you feel about running?
Well these spells are wizard but not sorcerer, and just for first level, other levels get progressively worse and worse. I could understand if named spells are off-limits, but why not let similar spells exist for sorcerers? (and they put a named spell in EE).
Alarm
Find Familiar
Grease
Identify
Illusory Script
Longstrider
Protection from Evil and Good
Tasha's Hideous Laughter
Tenser's Floating Disk
Unseen Servant
Yeah, OK, only two of those are named. And, no, I can't see why any one of those was excluded. Maybe a Dragon Sorcerer should have a more restricted list, but why would a Wild Sorcerer? If the point is for the Sorcerer to be more significantly different from other casters than they were in 3e, why not give the Sorcerer /some/ unique spells?
It is perplexing.
I used witch in the sense closer to me -someone born with a special gift that runs in the family- in that sense you don't chose to be a witch, you just are one, you don't learn to be a witch, you learn how to control and empower the gift, and no you don't sell your soul for it.
OK,yeah, that sounds more like a Sorcerer.
If you write up a sorcerer, and then add to you spells-known list "Find Familiar, Rope Trick, Unseen Servant" I just don't see how that requires any mental gymnastics in 5e that it wouldn't require in 3E.
Other than they were on the Sorcerer's list in 3e, of course.
(Yes, you GM has to allow this. The idea that all 5e GMs are such sticklers for the rules as written that they won't let you tweak your sorcerer's spell list seems very surprising to me.)
That is what's making me wonder. The big thing that 5e has really done for the game and especially for DMs, is get away from the RAW-obsession and back to openness. Not only not embracing that, but actively repudiating it is... unfortunate.