That's also what I thought - Wasn't Soma more of a way to make people question less and just remain in a blissed out but maybe sort of out of it state at all times ? Seems very different than amphetamines
I can only presume, based on timing of the talk being 1960, that his thoughts here link to mescaline and the practical utopia he talks of in Island, whose inhabitants make use of a local psychedelic. So whatever he must have said here had more to do with his later perspectives than his feelings around the island.