Fremont is a terrible DC for linode and it sucks if you are not aware of that when you buy a vps from them but I use the Dallas DC and haven't had any major problems to speak of in quite a long time (at least 5 AWS outages or more).
Apparently Fremont is their oldest DC and seems to attract the lion's share of the downtime. I've had 8 linode's running in their London DC for almost 3 years now and can't remember any DC related downtime. The only hiccup I've ever experienced is a host machine having disk issues once which meant they needed to move one of my vms. From being alerted of the problem to having the vm back up and running took ~45 mins with no intervention on my part.
tbh I have no idea as the London DC has been rock solid for me. On the odd occasion I've learned of Linode DCs having problems (usually here on HN) it seems to frequently be Fermont that's mentioned.
As for alerts, maybe they only automatically create tickets and alert users when there's a problem with a vm or the host it's on. Agree with you that doing the same for DC issues would be a good idea.
Fremont is by far the outlier here, its easily their most error prone DC. I'd highly recommend you move to another DC, all of which are much more stable.
Disclaimer: Customer for ~4 years, VPS in all DCs but Tokyo.
Which is funny because Linode has pretty bad uptime.
When I was on their Fremont DC it went down all the time.