Cool. The EU does have its [many!] faults. But they have a pretty good track record when it comes to consumer rights and consumer choice. Next up I'd like to see them do the same for the plethora of incompatible cordless power-tool systems out there as they did with insisting all mobile phones standardise on a USB connector.
If the EU standardizes on battery packs, Ryobi needs go get a free pass or extension of some sort. Ryobi have kept the same battery format for 25 years, whereas their competitors have changed battery standards 2 or 3 times during that timeframe.
Ryobi should not be praised for failure to innovate. They did not do this out of a desire to preserve compatibility, but rather out of cheapness.