It’s not usually the amount of texts that’s the issue, but the timing of those texts.
These limits apply to almost all providers, even including the government (albeit, those are for messages to just 1 number).
The reasoning is that stuff like newsletters or service updates are usually sent via group text, so a large amount of messages being sent within a short amount of time is often an indicator or such behaviour.
Members who have had this happen to them can get their services reactivated by contacting an agent.
Judging by the amount of people I see with this issue compared to others (like activating a new SIM instead of doing a swap) I’d say this isn’t a major issue yet.