Far, far less likely. Svelte has undergone some changes, and will continue to do so, but the latest round of change swung heavily in favor of USING THE LANGUAGE. Most of what you write in Svelte, with some notable exceptions, is vanilla JavaScript.
We in the Svelte world love it so much, it seems highly unlikely there will be any drastic switch from what we've all grown to love. (It's truly fantastic, give it a whirl: https://svelte.dev/repl/hello-world?version=3.5.3)
(Side note: I actually clicked on this link hoping Vue was learning a similar lesson, only to be disappointed.)
Hopefully they recognise their niche and stick to it. I'm particularly interested in Svelte for compiling down to vanilla WebComponents to be used in P2P apps (eg Holochain) where you want the end users to be able to modify components themselves.
Sorry, but seems Rich is not too happy with WC', if you want to do use a compiler to vanilla WC's I think stenciljs might be your best option. LitElement is also good - but it is not a compiler. Svelte V3 doesn't even have custom element section documented at all at the time of the writing.
There is also, Custom element API section that is "TODO". Yes I saw those options the first time, but woulnd't you say the documentation is limited ;) if such is the case.
So far I see 2 sentences related to the subject, compare that to V2 docs.
I will try to see how svelte performs for this, but so far Vue wc-wrapper seems to be the most promising option out of "non-wc first" ecosystems.
