Everyone is a little quick to presume Ottawa moves Bishop.
Another scenario could see the Sens move Anderson at the deadline.
There is no harm in the status quo for Ottawa.
Give Lehner a few more looks at the NHL level and send back to Bingo, leaving Anderson with Bishop as his backup. Bishop is an RFA at the end of the season, so there is no pressing worries about keeping him. Keeping Lehner and Bishop fits better with view of A Sens rebuild.
The only reason that this is being talked about is that Ottawa may need top four D, however the Sens have other assets to deal for that if the D proves too vulnerable early on.