Just because they're offering incentives does not mean there is anything out there to buy. You can even send out "BUY ONE GET ONE FREE" if you have nothing to sell.
Then you also have to consider all the trucks that were sitting in storage due to the chip shortage. Those have all disappeared, and reports are the chip shortage is over, so it is equally possible that there is a glut of new trucks headed to the lot that they need to move.
"Must act by April 4, 2022" can also have a couple different meanings. Manufacturers have been using that tactic since forever to create a sense of urgency in you so that you'll run right out and buy. This won't be the last time they offer incentives.
Another possibility is there won't be any trucks on the lot until April 5th, meaning the incentives are worthless.