Microsoft did not restrict them such that they could not make a new IP or games other than Halo. Basically Microsoft didn’t really care what Bungie did as long as they released 5 Halo games and met their deadlines. Bungie chose not to make other games at that time because A) in the beginning, they loved Halo and wanted to keep making Halo, only tiring of it when they finished Halo 3 ODST, and B) they felt that their studio was big but not big enough at that point to handle making Halo games as good as they were while also making new IP at the same time. For example, Bungie were in the planning stages for Destiny while they were developing Halo 3 ODST, and began some prototyping for Destiny 1 while they were finishing up work on Halo Reach, as Destiny and Reach use the same game engine. But the team they formed to do that for all that time IIRC was around 50 people. For reference, Halo 1 had between 50-150 people working on it.
With Sony, its still too early to know the terms as former employees are likely still under NDA or such, but I would say it is highly likely that Sony did restrict their ability to work on other IP. The reasoning for this is that Bungie’s announcement says they’re losing a chunk of their employees so they can form a different internal Sony development studio (not a Bungie internal studio) to work on new IP. If Bungie was not restricted in a way that prevented them from working on new IP (like Microsoft which did not say no to new or other IP) then Bungie would have formed an internal studio to do this, not splitting off one to go under Sony.
Either way, Sony’s approach is very clearly more aggressive.