At this point in 2042's lifespan, we're not getting any additional Portal maps. I feel pretty sure that ship has sailed.
But with any luck the next title will have a Portal mode and hopefully will see additional classic maps - it's clear that players want this, but all the work spent on getting 2042 up to scratch has taken away resource that might have been used to bring more classics to it.
I'd love to see some maps from BF1 and 5 too, BF1 had some amazing maps, and honestly, does it matter what era of soldier plays on them? A good map is a good map.