Rewriting a module from one tech stack to another is not much harder when that module was a part of a monolith and not a separate service, except that you haven't paid the upfront cost of bootstrapping a new service, putting in RPC calls, etc. And in any case, starting a project as microservices is already a bad practice due to a number of reasons, the most important for me is that it's hard to change module boundaries, which you will most likely get wrong in a new project.