Not to speak for Mason as I think he's still around on occasion but this build was released in 2012 with Vanilla Skyrim and before Dawnguard existed...so there is certainly some room for tweaks with the expansions and DLC as you're noting. All builds are typically fluid and can be adjusted by the player to make it their own so if that makes sense to you with the new content, then go for it.
Not to speak for Mason as I think he's still around on occasion but this build was released in 2012 with Vanilla Skyrim and before Dawnguard existed...so there is certainly some room for tweaks with the expansions and DLC as you're noting. All builds are typically fluid and can be adjusted by the player to make it their own so if that makes sense to you with the new content, then go for it.