Most of you (I think even Kaivax) are confusing two issues here:
Real skip to Renown 25 with The Severed Threads
During Beta, the Severed Threads reputation needed for a rank-up was set to 1 (3 for Paragon) while it was 2500 (7500) for the other major factions. This probably happened because the intention is to gain one Renown rank on gaining a rank with a Pact.So in theory you only needed 24 Pact reputation (instead of 24 Pact ranks shared between all three Pacts) to max the Severed Threads Renown.
I don’t think it happened with the smaller 50/50/50 rep from Azj-Kahet Rares, but when players had their first big reputation gain with a Pact (e.g. 2500 with The General from a quest), this was enough to skip to Renown 25 and unlock all perks/vendor purchases - for real.
This is the one that has been fixed (they set back the values to 2500/7500). I wouldn’t be surprised if the skip will happen again when players gain 2500 Pact reputation (e.g. from the WQ Weekly) with a rep bonus.
Fake Renown Ranks triggering Achievements
When players log between characters, some achievements tied to Renown ranks of new major factions seem to add up the existing ranks/reputation repeatedly, but different to the other bug this seems to be a Warband issue that is only triggering the achievements, not affecting the real reputation.