The release notes point to a switch to "Salsa" for JS intellisense. Salsa is based on the TS intellisense service (it is run by the TS intellisense service) and the same one used these days by VS Code. At least what I've seen in VS Code, Salsa seems fine with ES2015 import syntax and intellisense. (That said, almost all of my code is TS, so I'm not sure I've hit any specific use cases you are particularly looking for support in.)