The op means: the letters map vaguely to the sounds used to produce them.

Also speaking some Thai, I'm like you unsure this is any kind of useful insight. More useful would be that there's enough Latin alphabet signs in Thailand that all literate Thais can already sound-out English, even if they don't understand it.

I meant that it's not much of a conceptual jump for people with native literacy in abugidas to an English game like scrabble, since the writing system is already really rather similar.

and I guess because many of the words are not ones a native speaker would know anyway and are only learnt for the game.