A note on copyright
The right to make and distribute copies of a work is granted to the creator at the moment of creation.(“maker” might be more accurate. The Creator already created the building blocks for free and we just re-arrange them.) The right to copy (copyright) means physical, electronic etc. Copyright may be officially registered with the local government. This right to make and distribute copies means we are supposed to get permission, and probably pay a royalty, BEFORE copying someone else’s work.
SO, saying on a cover video “no copyright infringement intended” is polite, but wrong. You copied it and distributed it without permission. But you did give credit, which is nice.
HOWEVER, I too, have done piano covers of songs in this way. Why? Because if someone else posted a video playing one of my pieces, I would think it’s great. I would be glad they liked one of my pieces enough to learn it, and a cover video is a great way to share (and free advertising too, haha.)
I think if we always share the original web page of a created work, we will be helping the creator.