When it comes to coins from medieval Livonia/Estonia, I believe the two places in the title are the last two places missing from the catalogue, so this will (probably) be my last mention of new issuers to add.
Danish Estonia:
I have a request pending under Reval (https://en.numista.com/catalogue/pieces139636.html), and while the coin in question was minted in Reval, the sources I have found say it was used throughout Danish Estonia. That place existed from 1219 to 1346; it was eventually sold to the Teutonic Order, and later became part of the Livonian Order/Livonian Confederation. Foreign coins (like the ones from Gotland and Lübeck) were more popular than the locally-minted ones, but still, Danish Estonia minted a couple coins. And when I say a couple, I mean I have only found pictures of two different brakteats. I have yet to create a page for the second type.
Danish Estonia also went by the Duchy of Estonia; however, I would say to avoid using that name. Swedish Estonia (which existed from 1561 to 1721 and used Swedish coins as their main currency) also went by the Duchy of Estonia, even though the two places existed over one hundred years apart and were ruled by different countries. Using "Danish" rather than "Duchy" could avoid any potential confusion between these two places.
-----
As for the Bishopric of Riga, I am not one hundred percent certain if that should be a new issuer. That was a place that existed from 1186 to 1255; it was upgraded to the Archbishopric of Riga in 1255, which is already an issuer. As far as I can find, the Bishopric of Riga has only issued one type of brakteat, which is this one: https://en.numista.com/catalogue/pieces139635.html. Its request is currently pending under the Archbishopric of Riga, but I am not sure if an Archbishopric and a Bishopric are different enough to count as separate issuers. Either the two should be separate, or one should just be a currency of the other.
And... that is it. Thanks for reading!