The only concrete thing I know of is the decision by all the major retail brokers to suspend buy orders on CE stocks after 1/31.
As far as I know there is no concrete timetable to restrict trading in other tickers, let alone those with stop or yield signs indicating less current filings.
Any such restrictions would not affect DL and Arcaro and their peers directly - they could still snag and refurbish shells. WE (retail investors) just would not be able to follow them through the process. The NVSOS and other alerts would still be fully transparent, they just would not be immediately actionable.
I doubt that DL is winding down hos inventory due to these restrictions or prospective restrictions. He does not make his money based on whether retail can trade the shell, he makes his money by refurbishing the shell for the prospective merger partners who lack the ability to refurbish a shell themselves. My guess is that DL sees some advantage to advancing the status of some or all of his current shells before new rules go into effect, and therefore is focused on them rather than refilling his pipeline with early-stage candidates. Any new candidates would be 100% governed by new rules so there is no urgency to start any of those before those rulse are in effect.
If I could afford to buy all of them, I would not need to buy any of them and I sure wouldn't be spending time on the message boards!