If the number of phones is small maybe. Though I doubt they can just throw lithium batteries in a landfill in the EU.
There are manufacturer’s that produce different phones with the same name and different hardware for different regions but I could not find concrete info if there’s actual hardware differences for iphones.
Nobody is asking ‘software’ companies to support software they didn’t write.
We are asking hardware companies to support their hardware and not use different software as an excuse not to replace faulty hardware.
They can reflash their own software to test if needed.
Of course hardware vendors could be legally mandated to adhere to standards to make things easier.