We simply don't know what's going on behind the scenes. The impression I get is that initial development was rushed (big surprise) and they didn't build in enough flexibility. They could be doing a major revamp internally to get ready for the 2024 release, but who knows. They were bought out in April, between project planning, determining budget and establishing goals, there's a good chance any major revision, if any, was started months after they were bought out. Depending on the scope of the change it could be a months long project or a year long project.
D&D is a complex domain and is quite difficult to model in a way that it all works together, there's a lot of weirdness they have to figure out and testing any modification at all would be a bear.
The only ones who could provide more details are on the DndBeyond team and they aren't talking for obvious reasons.