Preventing a licensor from adding clauses may have been intent of the authors of the AGPL, but they aren't in a position to enforce that.
The license in question is not being called "GNU Affero General Public License + Commons Clause", which could be fought on the grounds of trademark violation — it's being called the "Neo4j Sweden Software License".
There's the theoretical possibility of a copyright claim for the text of the AGPL, where the AGPL's copyright holders disallow derivative works, but I'm pretty sure that won't fly for lots of reasons: not clear who has the copyright and therefore has standing, not original enough, functional rather than creative, etc.
ETA:
There may actually be a trademark problem here.
https://sfconservancy.org/blog/2022/mar/30/neo4j-v-purethink...
> But Neo4j consciously chose not to do that. Instead, they license their software “subject to the terms of the GNU AFFERO GENERAL PUBLIC LICENSE Version 3, with the Commons Clause”. (The name “Neo4j Sweden Software License” only exists in the later Court papers, BTW, not with “The Program” in question.)