So, something odd I just ran into: finished a Borg Alert in Alpha Centauri, started heading for Iota Pavonis to my next mission, and all of a sudden I get a loading screen. On the other side was one of the local Romulan Deep Space Encounters, except that I had never asked to enter one.
Is it possible that they've started auto-joining players on contact like they did in the old days? If anyone has a new alt, try hanging around one of the DSE ships flying around sector space to see if 1) it starts chasing you, and 2) if it pulls you into a DSE.
I was on a level 20 KDF-allied Rom, for the record, but if it's reverting back to old (very old) behavior then anyone in a zone intended to be a higher level than they are may be able to experience this.
If anyone else runs into this, give a shout? I'm interested in seeing if this is an actual thing and not just a one-off bit of post-patch weirdness.