The code section cited in Notice 2019-07 in reference to the phrase "used by the taxpayer as a residence" is §280A.  The answer to your question lies in whether the property was a vacation home.

The 250-hour requirement is in relation to the number of hours the taxpayer, his/her employee, independent contractors, and agent must have clocked in for rental services as defined in Notice 2019-07.  It's not about the number of hours the property was let out.