Okay, I see what you're saying now. Using the PRE_INPUT alias reverts the console title to its original value. (PRE_EXEC and POST_EXEC do not.)
I don't need to start a new console, or change UpdateTitle. I see the same thing in a Take Command tab.
This doesn't appear to be new behavior. I can reproduce it in v27, v26, v25, and TCC/LE v14.