I personally don't update Forge, unless there is a new MC-Version out (still running Dev-Environment on old MC1.4.6-Forge). I just don't want to depend on the latest Forge for absolutely no Reason (like many other Mods sometimes do). If one updates Forge to get access to a new and really needed Feature of it, then good, but if nothing Forgereleated is going to change at all, then better don't update Forge.
I can agree with a developer not updating to use new features if they don't need them, but users should always use the recommended forge because each update generally contains improvements and bug fixes which are important.