It does mean that OSMAnd won't know about it, but presumably there's a posted/signed detour that people can follow and OSMAnd will re-route them.

You could also do conditional restrictions (https://wiki.openstreetmap.org/wiki/Conditional_restrictions), so for example adding "access:conditional=no @ (2024 Jun 13 - 2024 Aug 30)" would tell OSMAnd not to route through that intersection for those dates