Adding to Steam costs $100+ USD per game; unless 'Melanie' gets a lot of donations that is doubtful to happen. If they want to start up a crowdfunding thing or something to make it happen then it is a possibility but according to them this has always been a passion project first rather than something to make a lot of money.
I know adding on Steam is a big thing for many and it is good for visibility, but that $100+ USD barrier is quite a bit. I suppose that's what itch is for ;)