A few things stand out in this story. Tegmark can't have been unaware of Nya Dagbladet’s association with a neonazi party in Sweden. The concept of "longtermism" which sounds all moderate and sensible, has been employed in undermining support for Ukraine, again mostly by hard-right groups. Longtermism is part of a constellation of concepts, the names for which concepts obscure their real purpose, more of less effectively. For example, mentioned in the article, is "ethnopluralism." If you dig deeper into "ethnopluralism you find it is to prevent "population replacement" and “contribute to a healthy population development, and joy and vitality for the people you belong to.”
Ick. This isn't going to get less ugly the more one digs in.