The hidden note updating the ticket and SLA time for quite some time, in fact I'm quite sure that this was before SolarWinds took over.
Did you upgrade from a version earlier than 11? If so, you would typically notice this change.
As for the alert levels being hard-coded, that's because this feature was initially implemented prior to SolarWinds and the requirement at that time was to have a few levels of alert.
I'm sure that if they were still developing Web Help Desk, this is a feature that would've developed to have an infinite-like number of alert levels.