Absolutely. It can allude to the fact that a lot of businesses and companies look for candidates who have good graphics skills along with UX and UI design skills. Having good graphic design skills can be helpful in cases of designing a visual library for a UI design. As a graphic designer, you will have a strong sense of typography, hierarchy, and layout which can help you design beautiful and neat interfaces. If you happen to be in a small startup, there will be a chance where they look for candidates with good graphics skills along with prowess in UX Design. Some knowledge on the graphics side of things will always prove useful to you. You won’t always be asked to design flows and wireframes and interfaces for an app.
There are times when you may have to come up with marketing materials for the app you are making. Brochures, leaflets, posters, business cards, presentations etc, are some of the things you may be entrusted with doing. In such cases, having a good balance with graphics and UX design skills is absolutely worth it. So yes, it is recommended and really, really useful if you can become both a UI/UX designer and a graphic designer.