That's where the retrospectives are good again, having that time every 2 or 3 weeks to ask questions like "Are we getting any value from the stand-ups?" Then could try not having stand-ups for a sprint, or indefinitely, and see if they're missed or not. Or try not having the project manager present at them for a sprint.

If a team has a good culture around knowledge sharing etc then quite possibly its not required, while for other teams that short time all together is better than nothing.