Musical interpretations are very personal. It's your personal thoughts and ideas of how a piece of music should be played. However, when you start using intellect and "oh this would sound different/cool/etc..." as your interpretive tools, you are no longer interpreting the music but forcing your will upon the written score. Sometimes that will is against what the composer has shown us in the music. There are general concepts to music that we should all be able to hear and create on our instruments
1) Notes ascend - you get louder as they go higher
2) Notes descend - you get softer as they go lower
3) Intensity = loud
4) Relaxation/release of tension = softer
There are others, but these are 4 basics that go along with the phrase in question with Lagrima.
Now, there are times when you'll actually go against these rules (IE - break them). However, the first question that one should ask is "Does breaking these rules enhance the piece?" If not, then you are probably over thinking the situation.
When in doubt sing the phrase. How do you hear it? How would you like to shape the melody? Singing will answer all these questions so you don't have to come up with an intellectual solution, but one based on notes in the piece.
Edit - Another thing, if someone is going to provide a musical interpretive idea that is different than the norm, for me they have to be able to support that opinion with musical facts from the piece of music. IE - I'm going to do abc because of xyz in the piece therefore I get this result. In addition, they have to be able to execute the idea comfortable and convince me. Sometimes people cannot do that. Or they may be able to explain why it should work, but when they play it -- it just doesn't work. Remember musical interpretation is individual. While the video in question is showing you a different perspective, it's up to you to decide if 1) You like it or not or 2) If it's a valid alternative to what you have been playing.
I'd argue, due to the amount of times you hear this phrase in Lagrima, that it might be interesting to incorporate the idea into 1 or 2 phrases that you feel would benefit from it's results. Would I do it for every phrase? I don't know, but I have my own phrasing of Lagrima
and I don't feel that it needs to be altered.