-1 for that. We don't put safeguards everywhere in Symfony for people implementing methods without respecting the return type. Adding it in a single place would be inconsistent (and adding it everywhere would be a huge pain to maintain)

It could also be considered a corner case. Checks like this is often not needed for methods similar to initializeBundles since those methods often uses adderMethods with typehints that works as safeguards. Since initializeBundles does not use a initializeBundle method I think we should enforce the type in another way.

It could also be considered a corner case. Checks like this is often not needed for methods similar to initializeBundles since those methods often uses adderMethods with typehints that works as safeguards.

Check in Symfony (and related libraries maintained by us, for instance twig) for the usage of any method returning something, and you will see that often is not justified in your sentence.

Closing for the reasons given by @stof

We don't put safeguards everywhere in Symfony for people implementing methods without respecting the return type

@stof check #18656, it's done for same reasoning right? So we have a safeguard here.. I guess it's not a big deal but perhaps it could require some convention (i.e. allowed to improve logical exception messages)...