On a more serious note, what is the procedure to get one of these dormant accounts? Is at all automatic and on the day I sign up simply makes it available to me? or is there some kind of internal system, or "drop" (as with domains) where these newly renamed accounts are made available? Transparency from Instagram on this issue would be best.
A bit pedantic but Warren Nyerges and his wife, Maureen Collier did not buy out the bank building and force the bank out of it.
Nyerges and Collier won, in court, reimbursement for their attorney fees and then had sheriff enforce the ruling who then proceeded with a foreclosure (which was on the furniture and not on the building).
Twitter no longer let anyone claim any inactive accounts. And only honour Trademark based claims if it's obvious there was intent to confuse and it's causing confusion.
Twitter no longer publicly allows anyone to claim inactive accounts. Informally, Twitter employees (and friends of employees) still have channels they can use to claim inactive accounts.
I have seen at least two instances of Twitter staff taking old, unused short handles after being hired there. But I don't know about the specific policy decision you seem to be referencing (and I don't know whether that decision exists).