PIPE shares re-legend after 90 days, if they don't sell the shares.
Have you not researched this?
The act of getting the legends removed from the restricted shares doesn't cause the dump; the desire to make a profit on their 60 cent shares causes the dump.
The de-legending is not automatic. The holder has to request, the company has to provide a legal opinion that it is OK, then the transfer agent has to allow it.
At that point, they have shares they can sell into the market (or use to cover a previous short position), and the 90 day clock starts.