Well, I'm not sure if you know this. But it's a fairly new repeater that's only been out for a year and they actually have been upgrading it. The no tone is an upgrade from the original which had no option for that at all. It also didn't have a squelch which is essential to a no tone system. So most likely the software hasn't been caught up yet.
And it's not like they gave you the function and no way to activate it. It's a small annoyance to deal with while they are putting more thought into the machine to give it more features than when you bought it originally.
When I got mine there was no squelch, no DCS, no microphone to talk into only program, it didn't have a no tone option and a few other small things. The menu system was still cluttered with another versions options which did nothing in this version and they cleaned that up. So my machine has had nice upgrades while you look at it as a basic machine because that's where they were in the ongoing development of this repeater.