Yes, I know about NeoX and was kind of surprised to not see it mentioned in the 3.0 announcement! As far as I know it's on the roadmap to be developed right about now... Q3 I believe.
And I do believe dynamic sharding is probably what you think it is too. It think it'll allow dApps to set up and close shards dynamically on demand. Probably not necessary now but seems like a useful idea. And... probably really good for marketing/price action ;)
I don't think this will do much for the price to be honest. NEO's price never really reacts to the news. I remember when the rebrand to NEO happened and it took a week or two before the news actually caught on.
True. NEO's price is incredibly news resistant! But remember what happened when that AntShares/NEO news did catch on! :D