I asked the same question when I had mine replaced. The general consensus was that it was not necessary. I ended up waiting about 2-3k miles before I changed the oil. The UOA did not show anything unusual.
Just clean the engine off before you begin. Then when it's dry, blow it off with compressed air.
Thereafter, just be surgical about your management of contamination getting into the area being repaired, then you should be OK.
I'm a little OCD, so if it were me, I'd wait till I was just about ready for an oil change before I started the work. Then I'd do one afterwards. My engine on the other hand would likely be indifferent if I was diligent about cleanliness before and during the repair.
I've got a big weekend lined up. M62 engine, plan to do valve cover, valley pan and the @#[email protected]$ crankcase hose and ccv. Should be a full day - maybe a day and a half if I take things slow..
Any time we did a VC gasket we waited till we were due for an OC and then changed the oil after we checked for leaks. If you work clean and neat, and don't drop any junk into the engine you should be OK. Me I suffer from some OCD so I wait till the OC is due.