FYI, the last two evenings while watching TV I have noticed my Echo Plus gen 2 updating the firmware. I haven't noticed any of the other three Echo devices (two Dot gen 3 and one Dot gen 2) updating, but if they updated around the same time I would not have noticed since all three or in other rooms. I do know that Alexa has had increasing issues with control of my Home devices (lights) in the past few weeks, so maybe they are working on that. Or perhaps Bezos Bozos just wanted to further muck up an already flaky Alexa!
You never know with Amazon. It is like a rollercoaster ride with them. Hopefully they made some improvements this time rather than just add more unnecessary features I will never use.