[WorldMaker]

enums and a couple others were a pre-1.0 Typescript feature when Typescript was first trying to figure out how standards following to be and also TC-39 was just "getting the band back together" to start work on what would become ES2015 (aka "ES6").

Since 1.0 Typescript has been following a plan that every feature needs to be on TC-39's standards track somewhere and since around 2.5/3.0 they've been even more strict that every feature needs to be at least Stage 3 in TC-39's standards track.

That enums still exist at all is mostly a testament to Typescript's backwards compatibility goals. A lot of 0.7-ish code will still compile today with the right flags and can be usefully upgraded by setting new flags one at a time. TS 0.7 code also won't look like modern Typescript, it's so far away now.