I don't think that saving children from a dangerous fall would make Walt unhappy, but I'm sure he would have come up with a better fix than these semi-themed rails by now.
Bob Gurr tells a story of Walt getting pretty ticked off at him for going behind his back and creating a prototype safety cage that would have fit over the astro-jets just to appease the lawyers. I'm sure Walt would have rather abided by the laws of common sense.
Personally I think the temp. railings look stupid and seem super unnecessary. For 55 years there have been no railings on that ride and now suddenly they need railings?? I think it's really an earthquake precaution of some kind, and they just aren't saying so.