technical detail: markdeck uses pandoc[0] as converter; and, yes, there is a LaTeX-Importer available, too (besides the Markdown-Importer used now by markdeck). So, on a per-file basis, it should be quite easy to support other input formats than markdown (restructerdText might be another candidate).

Embedding LaTeX in markdown might be a little bit more trickier, because we already use html-tags where markdown is not expressive enough... sigh

[0]: https://pandoc.org