Almost always, as long as the term change is not material. At least in the US.

Material changes require mutual assent. This case was about whether mutual assent existed. The court said "yes".

So no contracts were changed by one side without the other one signing off - the court found the other side signed off.

and sending a notification without any (reasonable) form of "has been read/noted confirmation"

email is notorious for arbitrarily not being delivered due to "spam/scam" filters misclassifying things

In this case, both users admit they actually read the notice, one after it was sent to spam, and the other it was delivered properly.