This is sad news indeed and as already mentioned by a few, it's impossible to really understand the decision without knowing the underlying details. However as a Journe customer and a (relatively new) member of a community that is by its nature meant to express views, I will say this:
1. FPJ is not dependent on PPro for its core business and the closure of a forum (after any initial sting associated with being labeled "amateur") should not, to a large degree, affect anyone's decision whether to buy his watches or not - in my opinion.
2. I do think this takes something away from PuristsPro - as a venture, taking away this forum, that is dedicated to a brand so externally PuristS in nature will hurt the site. I can only imagine that the site owner(s) are rational and so did not do this as an emotional decision. However, I can't reconcile why the "sponsorship" of the brand is needed. The only rational explanation is that FPJ is able to wield some power to close such discussions through legal means but that seems unlikely to me. The site of course could be run for passion rather than for commercial development in which case any decisions are personal and not wholly predictable.
3. As the broader rational response by the community is, in my opinion, to simply move the discussion to HoMe or perhaps back to the AHCI, the forum closure simply is a less organized way to discuss the brand which again implies something missing in the logic.
4. This event is neutral to my future purchases of FPJ timepieces. I do recognize that we (and I include myself in this group) community members can be not only passionate but obsessive about our horological habits. This is a bit extreme - (I am a bit nuts and I am comfortable in my skin) when compared to the mainstream FPJ (and similar) buyer bases in my opinion and not core (although helpful) to their business.
So the whole thing (absent PPro management trying to squeeze FPJ) seems irrational - and believing in rational management, it means that only part of the story is understood. Thus I remain confused.
p.s. If it is only down to a PPro management decision, and FPJ has no actual power to keep the forum from continuing, then I would hope that PPro management would consider a simple poll of the community as to whether such a forum is desired by the majority and then reinstate without sponsorship if that is the case.
All personal opinions based on imperfect information so apologies in advance for manifest errors of judgment! All the best.