It nudges you towards pure magicka or stamina builds in a meta that has otherwise become hybrid. I find that really weird. I can also assure you that self-heals on tanks are a thing. Coagulating Blood is a thing. Tanks invest into mag regen, but a higher stam than magicka pool for a reason. Maybe this heal is not particularly good, I don't know. It looks decent enough and it's useful to have something.

EDIT: I suppose if you balance your max stat to change on barswap, you can place this skill on both bars to cost different resources. It might be interesting to play with stuff like that, but realistically double-barring a skill is too much of a sacrifice. I've never found builds with hybrid options of very similar skills, such as stam burst heal + mag burst heal, nice to play. It's always felt like wasted bar space and added hassle of watching your resources. A good build can do perfectly well and is IMO easier to play if you statically match the regen of each resource to the skills that you use.

I can see that for the spammable, but not the heal ... unless I guess I was playing a healer. This just doesn't seem good for a solo player or a tank.

It's definitely interesting, although there will be much testing to be done before anything substantial can be said about it.