I personally would not expect any sort of 4runner incentives this year. Heck, even before COVID (when they were readily available) most were considered lucky to get just a few thousand off on them.
If you trade in your current car, I'm assuming you won't have anything else to drive, correct? If that were the case, I'd lean more towards trading it in now if you can find a new 4runner available at MSRP.
Have an extra car that my family is willing to let me trade in or just drive it until the market gets better. But like you said, I wasn't sure if 4runner will have any time soon. Wasn't sure if 4runner had great deals before the pandemic, but from reading what you said - it must have been not easy to get a great deal.