VMware KB: VMware vRealize Operations Manager 6.1.x upgrade hangs if expired projects are present
It seems if VMware supports truncating a database to prevent a 'waiting on analytics' hangup on a node restart then you should also support inserting those projects back into the database. Your tier 1 support actually advised me to have our DBA do that on his/her own...so I don't know what you're going on about.
Aside from that, I need to delete expired projects on a weekly basis and I plan on doing so through a cron job. I'm doing this because expired projects can cause an upgrade or node restart to hang (per the KB title).