Absolutely yes, I feel as if all of Solas’ elven knowledge should have been shared with a non-romanced, but friend Lavellan. The fact is that Solas’ knowledge is so important and as a good friend of Solas, I feel he would have been just as upset by male/non-romanced Lavellan portraying slavery upon themselves as he would a romanced Dalish.
I understand that he it was a spur of the moment confession, that he did it to cover his slip of tongue (sort of) and so why it didn’t technically fit into friendship dialogue. But I also feel that it put too much importance into the romance over his friendship. This is why Solas feels like a “canon” romance, because you miss out on some really heavy and important lore if you don’t.
So I don’t at all like how Bioware made it a romance exclusive thing, since Solas’ feelings and worries would have been valid within a friendship too.