Quintana didn't go in 2016 if that means anything to 2020. Also it looks like Quintana (assuming his team gets a Tour invite), Bernal and MAL will all be racing the Tour to Paris. I'd guess Uran as well. Higuita may or may not be racing the Tour. I don't remember what Quintana's reasoning was. However, IMO he's not their better option anyway. They'd be better off with Higuita, Bernal, Uran, Marinez and one of the Henao's.
Unless Froome is fully healed/healthy from his injuries, which is not guaranteed he may not be going for GB. The Yates twins and Thomas I would think will be going.
My question regarding Spain is, who are they sending for the ITT? I'd guess Castroviejo, but that will mean one less climbing dom. They could go with Sanchez, or maybe going with a full team of climber and pick someone later for the ITT?