Red Bull has a presence at ERX this weekend and I think will be involved with the Crandon World Championship.
They still promote a lot, but WRT short course truck racing the portfolio is rather thin. There isn't exactly a backlog of tv providers waiting to televise the Midwest league, for example, but their flirtation with it appears to be over. And the Frozen Rush isn't there, either. Menzies was the guy they actually sponsored, and... no Menzies.
Even a company as free with their sponsorship money as Red Bull doesn't appear to be interested in the sport right now. It's kinda discouraging.