I like your bullishness but I think we're still far off from BTC hitting 1 million, ie. I think there are more pressing matters that should be solved first.
6 months go I would have agreed absolutely, but it's pretty crazy out there. It may take 5 good years to get another fork in place.
Without having a proper scaling solution widely deployed anything below 0.0001 BTC is effectively impossible to transact. In my opinion thinking about increasing decimal precision will only make sense once we're close to making dust transactable again.
Lightning is round the corner. Next year it will start being used properly. I think we're very close now. And there is nothing blocking it's implementation. It's definitely coming.
Once we're there my educated guess would be that such a fork could be deployed fairly undisputed, as I don't see any reasons for contentious camps about decimal precision arising, making it easier and thus faster to deploy. Then again crypto is a weird place, so who knows what counter arguments against an increase of decimal precision arise. It would be interesting to see how much the effective impact on block size would be, for example.
I think there will be disagreement about whether to make it a one off 'doubling' of precision (float -> double) or a more permanent variable precision representation.
I can see arguments for both. Although - lol - a 'double'
should do it. They may find other things to do with the numbers.