Not all, just those that were rejected by ML.
So, if you upgrade a nomination after the 24 hour period it takes ML to process, it gets rejected by the community but approved by the appeals team, you don’t get the upgrade back.
If you upgraded the nomination before the 24 hours that ML takes, ML rejects it, you appeal and it’s approved, then you’ll get your upgrade back. If ML passes your nomination onto staff review and it was upgraded before being passed on, staff reject initially but appeals approve, you get your upgrade back.
Context is important to provide, as not all upgrades are given back on a successful appeal.