AFAIK older universal systems locked you out of approach mode if the internal almanac said you weren't going to have RAIM at the ETA, based on an automatic RAIM prediction when an approach was armed. Later revisions removed this restriction because it was outdated and from a time when the more accurate/up to date database was not readily available..... I could be totally wrong on that, but it is my understanding.
Are you going to not shoot the approach if it says no RAIM but the more up to date NOTAM says you will have RAIM?
No I wouldn't.
So, an out of date RAIM prediction says no, a more current one says yes, and there has not been a RAIM failure or warning, but you're going to turn around and go home if thats the only approach?
Why?
You've still got enough satellites to navigate and to tell if one of those is giving erroneous information - if you didn't you'd have a warning.