To be clear, I have no problem with mods, in contrary, I support modability, but imho its the devs job to add standard things.
Yes, it’s a very good and very smart move to make the game modfriendly, it will keep it alive for many years, look at Mount & Blade Warband, similar situation, a small dev studio with a publisher and a mod friendly game and it still lives and breathes, after 4 years, if you look at the original M&B even 6 years.
Even if they can’t get it in until release, it doesn’t mean, they shouldn’t work on it at all, in contrary they should and add it after release.