Do you guys think that there's a concerted effort to go after online Catholic communities by various modernist forces, in order to tear down our networks?
No. There is no evidence at all to support this. Te Deum was, beyond reasonable doubt, closed by the decision of its owner. Reliable sources (TD moderators) have said that the only person who could have put the forum into "Maintenance Mode" is the owner.
The recent changes on Fisheaters appear to be a new format that they are calling Fisheaters 3.0. As well as a new look, links to FE (eg. from here or from Google Advanced Search) now take one to the home page rather than the designated link. While this may seem weird, these changes were almost certainly made by the owner.
The only likely connection that I can imagine between CI and FE is that the owner of Fisheaters may have seen that Matthew had improved CI with format changes and was inspired to make some on her own forum. But it is just as possible that made her decision independently.