Basic definition of a skillshot is that you shoot a projectile that moves in a direction of your choice. Proximity self-targetting abilities does not fit in that description as you neither shoot a projectile that can be dodged, nor choose the direction of cast.
Vector skillshots weren't removed in my cleanup. Just moved further up in the page.
If you think proximity self-targetting deserves a page, fair enough but I highly disagree with its inclusion in Skillshot.