This comment right here - on the right track.
I think a lot of people forget how long the process of negotiating intellectual property actually takes as there's a need of an equal agreement from both parties, there may be clauses which we aren't aware of in terms of what Masangsoft can and cannot do, not only, but once finalised that it may take a while to find the right candidates for employment in various departments - such as frontend and backend. It could also be that these are not new employees at all and they're just using the existing ones from their current games to work on another project, making their time limited. Yes, quite time inefficient, but definitely money efficient. Followed by finding an appropriate business model to deliver it in on top of researching the game layout and brainstorming coherent ideas. It can be super time consuming. Fret not I haven't forgotten about the priority list this project may have been on (definitely super low, and I still think its fairly low).
There are other factors at hand as well, for instance the amount of old players they didn't expect and I'm sure this question has come across in one of their meetings ''Do we allow previously existing accounts (in the MVS version) to migrate to MVR?'' - some companies actually allow this to happen because they're great at inventing ways of making some of the money they're technically losing, back. They'd also have to keep us, oldies, pretty entertained through multiple ways - especially new content - because we're the ones losing the most, not new players, even if one could say our time has passed and we should let it on to the new generations (though I'm sure they're aiming for the younger target audience (12+) ). Nonetheless, it would just beg the question on how well they'd be able to deliver that.
I'm really curious as to what new content there can be delivered, since everything that they've showed us so far has existed previously in some form or another; or was discussed and never made; or should've been in the game a long time ago (a great example of this is the Replay System - happy for it, honestly). Releasing new parts won't be an issue at all, they can any time hire someone talented enough or take the easy route by simply doing a collaboration with a licensing party, which would be more efficient in the long term anyway. Though before any of this they need to address the major issues which have been talked about across the forum every single time, such as weapon balancing, bug fixes, resolution settings and pretty much the basics that were always a problem in MVS - some people don't want crazy new content but rather just fixes.