A (non-indexed) View cannot have two potentially writable table-targets at run-time. That's one of the reasons that Views with UNION
in them are automatically read-only.
I can think of only two ways that this could be done:
View Triggers: Create a View with an
INSTEAD OF
Trigger that procedureally decides which table to write to, (I cannot remember if this has to be an Indexed View or not), or ...Synonyms: Define your View's target through the use of a Synonym. Then when you want to switch it, simply redefine the synonym.