If the user didn't opt in to a notification, then by definition, it is unsolicited.
[1] In Germany, there is a specific section of the public code governing ToS ("AGB-Gesetz", part of the BGB). Among other things, it forbids "unexpected" terms, acknowledging that people usually cannot read all the ToS that they have to agree to in practice. Quite a few ToS have been nullified by courts because of that rule.