It could just have been one with a very large check.

It doesn't seem unreasonable to me if you have the resources. If I could've paid Apple to somehow just support OS X 10.6 forever I'd probably still be a Mac/Hackintosh user lol

There’s at least one customer somewhere willing to pay $1 million for that.

Plus adding a general feeling of confidence to the product as a whole. And safety knowing that you can upgrade for an extra 5 years of support if you need it.

The level of confidence is pretty incredible. Coming from someone who got hurt by CentOS.

One of the dirty secrets is that you don't need to back up confidence to sell it if you don't plan to be around when it falls apart.

Canonical has been around for 20+ years. It's not 150 years, but it's still something.

I don't understand your point, CentOS never had paying customers?

These kinds of demands are becoming more common in b2b software.