I would expect short term, some small spikes on last minute rentals and in general lack of vehicles for people with existing reservations. In the latter case, there's nothing that can be done, even for those who booked months ago, my guess is when there is a shortage they'll use status (based on number of rentals the renter has under their belt) followed by first come, first serve.
Depending on how long this situation goes on, it could have dramatic issues to prices and inventory issues. All agencies have some Toyota's in their fleets so no agency is immune, but even those without them could see their inventories receiving a greater utilization as reservation shifts will need to occur.