In D750/rP19987 identity was added to the mirage component so it had access to the classes list. However, we remove the classes list in the mirage filter, which seems pointless if we just add it back later. Here's the comment from rP15612 explaining why the classes list wasn't included in the mirage:
Select a subset of identity data. We don't want to have, for example, a CC mirage
that has also the CC class and then prevents construction of other CCs
However, the mirage filter doesn't include BuildRestrictions so it's not looked at in the distance check (of BuildRestrictions) and it doesn't change the entity counts (of EntityLimits), and it does include Foundation so it doesn't change the entity limits (of EntityLimits). So already this doesn't happen. (It would've been broken by D750/rP19987 if it had.)