I'm a backend guy, I been working on backend for the last 10 years or more. In the last two projects, I had to take the lead on the front end development not only by deciding the tech stack but also coding the complex parts and also helping the front end guys to solve some problems, even when this is requiring from me extra effort I'm really happy because I'm learning a lot about web front end development which it's becoming more robust and nice to work these days with libraries like react and frameworks like angular.
So as summary, yes, I think that it's an opportunity that makes you to grow as developer and helps you to help more to estimate those tasks that are outside of your "confort zone".