Tobi_444
“During the Third Shinobi World War, both Rōshi and Han demonstrated the ability to activate Tailed Beast Mode as a chakra shroud around themselves without physically transforming their bodies.” I don’t think Roshi can summon his full tailed beast transformation. He can only use the chakra shroud. He does NOT have the cooperation from his tailed beast. The beast certainly wouldn’t be helping him in his fights. Son Goku hates humans at this time. Since Roshi does not have its cooperation, it must be stuck behind his seal which means it cannot physically manifest or talk out loud like this chapter implied.