I rather hate this way of phrasing the argument. Basically, every town and city does this. Free cash represents money that was allocated but not spent. And it is typically used against the next years budget.

If we want rental relief, that should just be put in the budget at whatever level is appropriate and funded the way we fund all other budget items.

Basically, we should include in the budget all the items that are desired (affordable house, pre-k, rent relief, whatever) and separate that from the source of funds.