My team is one that had to expand under those brutal rules, so I will admit my bias.
Just like there's a difference between Vegas and Seattle. There's a big difference between, say, Anaheim and Columbus. I'd have to go back and check but the 93 expansion rules were slightly worse than the 2000 rules IIRC. Anaheim made a cup finals appearance in ten years. Won a cup in 14 years. Columbus has been a team for a quarter of a century and they haven't even gotten close.
Yeah the Vegas and Seattle rules were more favorable than they've ever been but all it did was give both teams the opportunity to be more competitive than previous expansion teams. Neither team was gifted a contender by the NHL. A lot of things went right for Vegas out of the gate:
1. NHL teams weren't judicious enough regarding their own assets and they didn't plan well enough ahead of the Vegas expansion draft (Anaheim in particular sat on their hands with their abundance of young defensemen and an NMC on Bieksa that required a protection slot). Vegas got a lot of useful players, but the majority line was they'd be a bad team for years.
2. That same group of players came in with a huge chip on their shoulders and something to prove. This led to a lot of them being motivated to reach new levels in their game that was either permanent or for a lot of guys was a short term exercise in playing over their heads.
3. While it's grim to credit a tragedy for on ice success, the Mandalay Bay shooting was huge for galvanizing that first year roster and fanbase by establishing a really strong symbiotic relationship. The team helped the city heal and that crowd drove that year 1 team big time.
4. Gerard Gallant is no one's long term solution but he's proven three times to be a great first year coach.
5. Because of that year one success and a lot of players having career years on top of a huge bank of future assets, Vegas was able to leverage a lot of futures and cast off players to acquire star talent. McPhee and McCrimmon had the green light to aggressively pursue trades and free agency signings and burn all futures in the process and they wasted no opportunity to do so. They took big risks with big rewards but they also have arguably the weakest prospect pool in the league as a result. Third rounder Pavel Dorofeyev emerging as well as he has was a stroke of fortune.
6. Moving on from Gallant after the team was starting to come back to earth with him seemingly happy with how his team performed in bad games, the team jumped at the opportunity to get Pete DeBoer, who is an upper tier coach but just didn't have the adaptability and capacity for making adjustments to get the Knights across the finish line.
7. In the same vein, Vegas jumped at the opportunity to hire Bruce Cassidy when the opportunity presented itself. Cassidy's systems, to me, were the biggest determining factor that got Vegas their first cup. Vegas doesn't get that far without the foundation that McPhee, McCrimmon, Gallant, and DeBoer set. The NHL had nothing to do with that.
By contrast, Seattle was a lot more conservative in the expansion draft by design and through the other GMs being far more prepared the second time around. They haven't been as aggressive in the transaction market and as a result they're nowhere close to contending in spite of having the same expansion draft conditions.
I think they're an example for why these new rules aren't that bad going forward since we're definitely getting at least two more expansion teams. Seattle was more competitive out of the gate and had some playoff appearances to generate excitement and connection with the local fanbase but they still have a long road to cup contention. The Vegas story is one marked by almost everything going perfectly and ideally with a few minor missteps along the way.