Yes, that will probably work. Of course it depends on exactly why react-native-gifted-charts decided to depend on react-native-svg version 13.6.x. It could be they found some bug when using earlier versions, in which case you could run into that bug at some point. It could also be that that was just the latest version at the time the Gifted Charts project was releasing the latest version, so maybe things will work fine with the slightly older version.
My theory is that it might be slightly safer to stick with react-native-svg version 13.6.x, since that’s what Gifted Charts says it wants, and it should in theory be backwards compatible with 13.4.x. Also, since you need to build with EAS Build anyway you won’t need to ensure you’re using exactly the right version to make sure it’s compatible with the native code compiled into Expo Go. The downside of using 13.6.x is that you’ll get expo-cli doctor warnings in your build logs with Expo SDK 47.
Anyway, either approach will probably work.