I think 90% chance of apple going for the EU-Specific model just like they did for Digital markets act, 10 chance of screws, 0% chance of actually popping the back cover off with bare hands.
For Samsung, 50% chance EU-Specific models 40% chance screws, 10% chance back cover tool-less removal. (Edit: typo)
As for other smaller manufacturers, probably just 50%/50% either screws or tool-less back cover removal.
I’m not sure why you’re worried about the connector since USB-C is mandated. Batteries will likely still be model specific since they’ll need to come in different shapes and sizes depending on the model and it’s internal hardware layout. I’m sure they’ll just use standard connectors on the battery itself since there’s little upside to engineering something special when the battery is already going to be specific to the phone.
I can understand your perspective.
My concern is from a tech support perspective I’ll be required to stock at least a few of each variation and need to teach people which ones and how to replace it. Plus the ecological concern of perfectly good batteries are going to waste because the next model can’t use them.
And I’ll inevitably have clients that will attempt to use the wrong one while on a mission critical trip to somewhere. And of course it’s not available anymore or some other road blocker.
This problem was mostly solved ages ago in other small electronics with things like AA batteries being a popular standard.
So I’m hopeful for a future where there’s an AA equivalent for phones and laptops.
The connectors were just an example of how manufacturers prefer proprietary solutions because of profit, and how it needs regulation to prevent such things