I would honestly support this if Pokemon were:
A) a zero-sum game
B) a game with a low random variance
This style of tournament is a great way to determine who the best player in the room is in these situations. The swiss + elimination model, on the other hand, was designed to determine the best player when a lot of inequalities and luck are involved. By adding a "safety net" to the game, such that players who lose one round are not out, the best players will eventually "bubble up" - at least, that's the game designer's theory. It works pretty well in statistics, though it really requires a few more rounds of Swiss than most Pokemon events allow by the number of players. I don't remember the math off the top of my head, and it does have to be adjusted based on a common-sense factor for variance, but a good example would be what a 100 person Regional bracket should be.
Really, with 100 people, you should be playing 7 or 8 rounds of Swiss, and cutting to top 32. In 8 rounds, with the luck factor in Pokemon, you're not going to reliably find the top 8 or 16 players in a bracket. Top 32 is going to catch some flies, but guarantees all but the unluckiest of the good players to make cut. A best of 3 format is then used.
The other option, which is commonly used in fighting game tournaments (which have low to no luck factor, but are very unequal in sides) is the double elimination structure. I'm really surprised Pokemon has not tried, even at the Professor Cup or a side event, best of 3 double elimination as a format. With 100 players, this would only play 7 rounds of best of 3 to determine the winner of the event, and after you've lost two full matches, you're off to side events or home early. I really feel like this format could be a good thing for Pokemon.
Now on the topic of Swiss and tiebreaks - the current tiebreak system is too random, because you cannot choose your opponents. The only way to really reduce the impact of tiebreaks is to increase the size of top cut; you will always have ties. The fact that there are so many factors that determine the winner of a match really make opponent's opponents a VERY poor tiebreaker in a TCG, so enlarging top cut makes this TB less serious. There really are no good tie breaking methods that suit random, non-zero-sum games other than playing them out, and even a single game doesn't always determine much, so the best way is to just get the tiebreaks out of the way, and enlarge the top bracket. When tiebreaks ARE needed, some algorithm based on event, season, and lifetime ELO ratings is probably best, but it would take some time and a lot of data to properly develop one.