It's happened to me several times before, although it's always been one flight crew member, so not a big deal since the one crew member can get most of the work done besides the briefings.
Originally Posted by
enviroian
I must just be an outlier then as I’ve had more times than I care to remember when the gate agent would hold back boarding until all crew members arrived.
I wouldn't say you're an outlier, more often than not in my experience boarding is delayed until the crew member arrives, but it does happen (and often to no clue where the remaining crew even is).