getSiteLinkPageName should not need to load the full entity. We can use SiteLinkLookup here. (yes, that has the issue that we still do not badges in the SiteLink objects here -- which we really should fix!) But if all we want is page name, then SiteLinkLookup would work and would be less evil than loading the entity.
see T108841 where it has become an issue in the database logs. mw.wikibase.sitelink is used a lot on Russian Wikipedia.