WordPress sites' oEmbed doesn't work in any context I've tried

Some testing on a local site:

<?php
var_dump(wp_oembed_get('https://chronoto.pe/2015/12/26/our-star-wars-holiday-special-the-new-inquiry/'));
var_dump(wp_oembed_get('https://hacktext.com/2015/03/the-myopic-web-shrinking-the-filter-bubble-with-dropcat-2212/'));
var_dump(wp_oembed_get('https://aramzs.wordpress.com/2011/12/15/buying-books-online-is-better-for-authors-better-for-the-economy-and-better-for-you/'));
var_dump(wp_oembed_get('https://www.ads-software.com/news/2015/12/clifford/'));

Results in:

bool(false)

string(618) "<blockquote data-secret="f7mvTj8w4S" class="wp-embedded-content"><a href="https://hacktext.com/2015/03/the-myopic-web-shrinking-the-filter-bubble-with-dropcat-2212/">The Myopic Web: shrinking the filter bubble with Dropcat</a></blockquote><iframe class="wp-embedded-content" sandbox="allow-scripts" security="restricted" style="display:none;" src="https://hacktext.com/2015/03/the-myopic-web-shrinking-the-filter-bubble-with-dropcat-2212/embed/#?secret=f7mvTj8w4S" data-secret="f7mvTj8w4S" width="474" height="267" title="Embedded WordPress Post" frameborder="0" marginwidth="0" marginheight="0" scrolling="no"></iframe>"

string(243) "<a href="https://aramzs.wordpress.com/2011/12/15/buying-books-online-is-better-for-authors-better-for-the-economy-and-better-for-you/">“Buying books online is better for authors, better for the economy, and better for?you”</a>"

string(508) "<blockquote data-secret="Jxmna0v58Z" class="wp-embedded-content"><a href="https://www.ads-software.com/news/2015/12/clifford/">WordPress 4.4 “Clifford”</a></blockquote><iframe class="wp-embedded-content" sandbox="allow-scripts" security="restricted" style="display:none;" src="https://www.ads-software.com/news/2015/12/clifford/embed/#?secret=Jxmna0v58Z" data-secret="Jxmna0v58Z" width="474" height="267" title="Embedded WordPress Post" frameborder="0" marginwidth="0" marginheight="0" scrolling="no"></iframe>"

So it looks like one of my self-hosted sites can be embedded, but one can’t. And my WordPress.com site can’t be embedded at all. But WordPress Core’s announcement can. Totally unclear on what differs between these sites.

The aramzs.wordpress.com site is supplying the following provider:

https://public-api.wordpress.com/oembed/1.0/?format=json&url=https%3A%2F%2Faramzs.wordpress.com%2F2011%2F12%2F15%2Fbuying-books-online-is-better-for-authors-better-for-the-economy-and-better-for-you%2F&for=wpcom-auto-discovery

Which doesn’t supply the embed block. So this feature isn’t rolled out on WP.com yet?

While the embed endpoint on chronoto.pe just fails out completely, so the problem lies on that side?

Ok, so did some willllllld plugin testing.

1. the oembed endpoint is incompatible with running v1 of the WP-API plugin from https://www.ads-software.com/plugins/json-rest-api/.

Ok, good to know. I mean, 10,000+ active installs of v1, but I guess they are just not going to use oembeds? And at least it fails gracefully.

2. Some weird interaction between WP-API v1 and Yoast SEO plugin means that if you are running both, you can’t just turn off WP-API v1 as a plugin. You have to turn off WP-API v1, and then the Yoast SEO plugin, and then you can turn Yoast SEO back on and everything works as expected.

This doesn’t make a ton of sense, but whatever, at least I’ve figured out the problem and v1 *is* technically depreciated, so this is a non-priority to deal with all around.

This just leaves the question of WordPress.com. Can we confirm that the oembed feature just isn’t turned on there, or am I missing something?