Most events do cater much more to newer players. This one is the exception. For example, in the trainer dungeon event that just ended, I only used one general for the battle so as to make the battles go faster. While that one general was a UR Master Strategist for the last opponent, I pulled her off in favor of SSR Takeda Shingen of Kai for three other opponents (less reflect damage, still powerful enough to one shot everything, and easier not to have to reshuffle gear), and some random archer who didn't even have any gear equipped for the first three opponents.
Furthermore, a new player and an established veteran getting exactly the same reward will tend to reduce the power gap between them, as the new player has far more use for the same reward. While new players were getting new generals to level 55, I was mostly using the experience cards to level up random spare parts that I'll probably never use. While new players were using the gold to level up buildings or forge up their best pieces of gear, I was spending it on alternate pieces of gear so that I could have level 65 pieces of gear for my defense team. That reduces the power gap a lot.
Even so, it's not like this event is asking you to beat Date Nami and Date Masamune from the end of campaign map 6-4. You can take multiple battles to do it. If it takes you five battles to beat the end boss, you can still beat it. The first time this event ran, it took me five battles to beat the boss at the start of the event, which I got down to 2-3 battles by the end of it. That was still enough to get some good rewards. That's not nearly as fast as beating the boss in one battle that takes two rounds like it was the second time the event ran, or invariably beating the boss in a single round before it even gets to attack like I do now. So while this event is tilted toward the more established players, anyone who has been playing continuously for a couple of months should be able to get some good stuff out of it.