They are indeed, that flight will remain in t1, with all other SWISS flights.
I would not be surprised to see BD flights move (back) to T1 again. With the DC lounge bing accessed from T1, as before. I assume this would still be possible, after the reconfiguration of T1 over the past 2 years? Moving WW and BD to T1 would probably give easyJet a bit more scope for growth.