When the project we are following no longer runs the roadmap, the community starts to become inactive. That is the most dangerous.
The roadmap is very important, not a few projects go off track from their roadmap, but sometimes it is necessary because things in the field are different from what they have compiled so that they leave the roadmap.
Indeed this is worrying and there will be indications of a Scam, but before you say a scam, take a look and learn what caused them to come off the roadmap. And of course, the CEO or the project team will explain why they left the roadmap.