If we do ever get a standalone, people will still complain, no doubt the same complaints they had about the previous standalones (poor computer integration, high cost, limited features compared to software solutions, doesn't sound as good as the 3000, doesn't have the same 'swing', etc).
There's clearly 'a' market there for standalone MPCs, but as jpeg says, it's very niche (a niche within an already small niche!), and I do wonder how many of those people will simply prefer to stick with their legacy MPCs regardless of what Akai may or may not put out.
I've seen many post on social media saying "Is it standalone?"
I wouldn't take much notice of that, complainers are more likely to complain. And out of those 30 facebook commenters asking for a standalone, you can bet only 3 or less of them will actually buy it if it ever did come out (trust me, I know this from making products based on forum requests, MPC Stuff will tell you the same).
Akai will have done the numbers, they won't base product development on social media requests. There might only be 500 people out there who would consider buying a new standalone MPC. You do have to wonder how many people even notice or care about the MPC market (in the general scheme of things) - it's certainly nowhere near as popular as it was 10 years ago.