Any Experience with LED grab rails?
Batteries Not Included
Actually, maybe batteries are included, I actually don't know. But I do know it is battery powered.
That is very, very good from a safety standpoint - electricity and water don't mix, so any mains-powered device in a bathroom has to be built properly, and installed properly, to be safe. Battery powered devices (or at least, devices like this powered by AA batteries) are pretty safe.
However, as crazy as it sounds, that may be really bad from a usefulness standpoint. Specifically, the batteries will wear out. I would guess they will last somewhere between a week and a couple of months. Once they wear out, they will need to be replaced, probably several times a year.
Do you think your in-laws will change the batteries? If they will, great. If they won't, then you have overpaid for a grab bar to get a temporary gimmick.
A more expensive (because you'll need professional installation - my understanding is that in Australia homeowners can't do much electrical work themselves) solution is a ceiling light with a motion sensor. These are quite common in public bathrooms, but there is no reason you couldn't have one in a residential bathroom. Then if one of your in-laws wanders into the bathroom in the middle of the night, they will get the full bathroom light instead of (essentially) a small flashlight.