I think they will show 3 or more versions like Rivian. Tesla is about to loose that segment to them if they don't have something quick. Showing the variants (including SUV) will undermine Rivian even if Tesla only starts with one initially. Those couple more prototypes are worth it just to crush competitor dreams. Ford can expect that rivalry too.
You could be right about showing an SUV and there is some logic to showing both at once (and maybe other variants too).
They may even start producing an SUV at the same time as the pickup but I doubt it since it is easier to get to high volumes first with the pickup and then introduce a variation (like the SUV) and then maybe other variations (different pickup and SUV sizes).
Either way I don't think there is much risk of losing the pickup/truck-based SUV segment to Rivian given its pricing and other factors, although I do hope Rivian is able to get a decent number of sales since we need more EV companies to enter the market.