Yes, Organic Maps is a fork of Maps.me. The original Maps.me was acquired by Daegu Limited, a subsidiary of the financial services company Parity.com, and they stopped publishing source code afterward.

- Press release: https://www.londonstockexchange.com/news-article/MAIL/mail-r...

- OSM removed from Maps.me, then re-added: https://github.com/mapsme/omim/issues/14076

- No more source code releases from Maps.me: https://github.com/mapsme/omim/issues/14157