Apple has a general policy of not commenting about features in any future releases: they will rarely even say something currently in WebKit nightlies will be in

Apple has a general policy of not commenting about features in any future releases: they will rarely even say something currently in WebKit nightlies will be in the next release, so it's merely keeping with their typical form of not making any comment about future products/releases. As such, I'd read absolutely nothing in to them refusing to commit to supporting it in a future release: that's just their normal behaviour, because per Apple policy they cannot. What actually are signs (whether they're implementing a given feature—typically publicly, whether they're sending detailed feedback on the spec, and what they're willing to say about implementing it off-the-record in private) are all there for WASM. I would be entirely unsurprised if Eich had off-the-record confirmation that it will almost certainly ship in Safari 11.