As part of the project to use Parsoid everywhere, we are bridging HTML output differences between Parsoid and core parser. One of these is in the HTML generated for media output.
As part of T251641: RFC: HTML element for inline media from wikitext, where we initially wanted to switch core output to <figure-inline> tag for inline media, after TechCom review and discussion, we decided to switch Parsoid back to <span> tag instead. The change in Parsoid will come with a version bump as well.
Before we roll out this change in Parsoid, we need all Parsoid clients to be prepared to handle either <span> or <figure-inline> tags for a brief period. Same with any necessary CSS selectors. Presumably, this will be a simple change.
I've created a common task and tagged all known Parsoid clients. Feel free to create a specific subtask for your own client, if necessary.