Agree, “get all actors” probably not the best here. Although just for future reference and to disseminate knowledge, I did some research on that node and apparently it is not as bad as people on forums and answerhub have made it out to be. Here is a link to someone who looked into the back end of that node and basically this is the important part I gathered
"The GetAllActorsFromClass Node uses a TActorIterator and ultimately ends up passing the specified class and through to GetObjectsOfClassThreadSafe, which is the workhorse that loops through the class-specific hashmaps stored in the FUObjectHashTables singleton."
Here is the link to the entire document