To my way of thinking, I think the only thing an ARC owner would have to worry about are proprietary parts. For example, early CD players and Analogue Modules that you can't get anymore. And likely the new ghost displays. With the schematics however, I suspect a good tech would be able to troubleshoot and repair just about anything.
When the PS went on my SP3a a while back, I found a good shop in OR who did a really nice job on it.
I feel for their longtime employees, vendors and suppliers though.
I read someplace (Fb?) that their CEO was "relieved of his duties".
Happy (and cautious) listening...