It's bad, but I'm not sure it's that bad. In B2B land, loads of contracts have a code-in-escrow clause just in case key people die or the company goes under. One of the key attractions of Open Source is that if the people building it die or don't want to support the tool anymore, you can keep going yourself.

This would not be that different, right?

What's going to happen to all software updates and remote services if Tesla goes bankrupt ?

Presumably whichever auto manufacturer buys Tesla will issue an update to make your dashboard display a Ford logo (e.g.).

It's problematic for a company to have EOL plans not because people will assume they will go out of business, but because they might not be able to actually adhere to those EOL plans resulting in a much larger mess than what would have happened if they stayed silent.