Not true, restrictive states had significantly lower mortality. Mask mandates being the most significant factor. The largest gaps in mortality occur in the latter half of 2020 and the latter half of 2021, during Delta.
The sea surface temperature data is from NOAA and the sea ice extent data is from JAXA. His claims are not difficult to verify, if you follow the citations.
https://jamanetwork.com/journals/jama-health-forum/fullartic...