All true. But there were reasons Tesla wasn't prioritizing Semi. Lack of batteries, of course. But also, it appears that Musk has been cautious about the economy, even before the coronavirus.
I suspect batteries (volume and tech) are the number 1 issue, with needing to line up a place to produce it (prob GF Austin), improving prototype design to get it production-ready and possibly not taking on too many production ramps at once playing a supporting role.