We’ve this changelog link: https://www.designer.io/en/changelog/ where you can find everything that has been made so far. Unfortunately, the roadmap is not public.
In case you are curious (I just searched on the page), it seems that this improvement was added at this point/version:
Jan. 29, 2019
With this release we are focusing on internationalization and some long overdue additions and optimizations in this regard. The first being the support of right-to-left (and top-to-bottom) languages, which finally enables to use scripts such as Arabic, Hebrew and Persian in Gravit Designer. In addition, we also included many other non-Latin characters sets, including Japanese, Chinese, Bengali or Georgian, to name a few.
But we didn’t stop there: The Cloud dialog received a massive overhaul with some new functionality and we have some new controls for text layers in the Inspector, including some advanced options like subscript, fractions, and paragraph spacing.