I'm a professional PCB designer among other things. Most of what I have learned came from hard-won experience designing PCBs for projects done for myself and my own education even though a custom PCB was hardly cost effective in a commercial sense. They were just much cheaper since my time was free. They weren't useless projects in that what I made was not easy with off the shelf parts, but it would have been possible and there wasn't a timeline to pressure me yet.
But I would not be a professional PCB designer now if it had not been approachable to someone without a budget but with plenty of time and motivation. I've basically spent as much money learning how to make PCBs as other people spend on things like ski trips or going on vacations or other hobbies. A free fab and tools to create designs is a godsend when designing these things is something you want to do for interesting experiments and learning in an otherwise totally inaccessible field. Even if you think now one needs a masters or PhD to do this right, being able to fail cheaply is a pretty amazing learning tool...
That's what this announcement means to me -- free fab means I can finally learn how to do this and get good enough at it that when the time comes that this is a better solution than trying to combine off the shelf functionality I will be well positioned to take advantage of that change.
I am thrilled to release open source designs for cool chip functionality once I'm skilled enough to do it and the only way I'd get there is if the direct cost to me was nothing (even if it's slow).