Interesting parallels between the two. I kinda got the vibe that Solas saw Mythal as a mother figure or mentor in some respects. There didn't seem to be a romantic vibe there. So we have the two 'children' of Mythal with mirroring scenes? No WAY that is coincidence. Remember, Morrigan started off as this snarky, do evil unto others type. She absolutely HATED helping others, and disapproval was her natural state. They have a shirt, for Pete's Sake!
On the other hand, we have Solas, who started off as this friendly but distant apostate who practically BLEEDS approval at every step. Yet in the end, he's so focused upon his goal that even to a lover, another elf, or a FRIEND he comes off as haughty, prideful and dismissive. Both tell you to live well if befriended, and BOTH deeply desire friendship in some form...Morrigan, who never understood it, and Solas who was alone for so long that he craves it. Yet, at the end of Inquisition...Morrigan is a profoundly changed woman who had a nice helping of Humble Pie (the rest was downed by dear sweet Fiona, who was given a much larger share seeing as she did EVERYTHING she could to EARN herself a slice, DIDN'T she?). Solas? No matter what, he puts himself on a course of self destruction...oh, and that little thing about WORLD DESTRUCTION...and turns his back on his friends to accomplish his goal.
Even IF the whole bit about Morrigan being given a part of Mythal's power turns out to be untrue, SHE in more ways is a better inheritor of Mythal's legacy than Solas. SHE represents the virtues that Mythal herself did once upon a time. Solas represents her Vengeance. I AM curious if the two will come face to face in the future...it DOES seem that both Mythal and Solas were pushing for SOMEONE to drink from the Well, but Mythal seems VERY entertained if the Inquisitor does. I am starting to wonder if HER goals are the same as that of Solas...hmmmmm....
I think Solas MEANT what he said...but again, I think he fails to understand the full implications of what is to come. He is literally going to war with the world...TWO in fact...the one he destroyed...and the one he is PLANNING on destroying.