the objections raised here are FUD, probably sourced from the fossil gas industry lobby. heat pumps are one of the most no-brainer ways to combat climate change. they're cheap to buy and operate (especially mini splits), safer than alternatives, better for air quality, and become better for the climate as we transition to cleaner grids.
source: I did a lot of research and modeling work on, among other things, heat pumps as part of Rewiring America.
I don't know how practical that is - would it need to be pressurised more than natural gas, and would the hydrogen be OK (that is, not leak out) in the existing system of pipes?
Time will tell if it all becomes reality.