I don't see Alan as Takuto, for a number of reasons.
The reason Satoshi vs. Takuto played out the way it did was because there was only one episode to knock Satoshi out of the Sinnoh League. Every other full battle (excepting the similarly one-sided Shinji vs. Shirona/Jindai) has two or three-parts for a reason. Assuming there are six episodes for the Kalos League, we've already gotten past Tierno, Trova, Ayaka, and Shota in four. That leaves two more for a Satoshi vs. Alan final, and that would mean we're getting a proper battle.
Takuto was also far out of Satoshi's League and that was obvious from the minute Darkrai knocked out Heracross despite the type disadvantage. XY&Z023, on the other hand, shows Onvern, in its first acknowledged (meaning the writers were fully aware of this) trainer battle, putting up a good fight against Alan's more experienced Metang, to the point Alan admits that he almost lost. That whole scene shows that Satoshi is fully capable of fighting Alan on an equal level, even when he's not using Gekkouga. So even if Alan is stronger now, he's not by such a margin that Satoshi couldn't catch up to him.
Takuto was supposed to come across as unbeatable, Alan is not.
Story-wise, it doesn't make sense. Alan's main reason for even entering the League in the first place was facing Satoshi, because Alan respects and acknowledges Satoshi's strength as a trainer. If Alan ever felt that he was capable of sweeping Satoshi 6-1 or 6-2, like Takuto did, he wouldn't be so interested in fighting him. Moreover, Satoshi has already fought and lost to Alan twice before. Satoshi vs. Alan has been hyped as one of the two most important matches of the Kalos League, the writers aren't going to treat it like a throwaway the way they did Takuto's battle.
Now, Alan could still very much win. But if he does, it'll more likely be a close, 6-5 battle rather than a one-sided stomp. Alan would be Tetsuya in this scenario, not Takuto.
Wow Ash you've been sweeping your early opponents. Definitely disappointing because it's rushed, and Trevor lost very easily as well which is such a huge waste of him as a character since he had no other Pokemon revealed besides that Charizard of his.
The episode revealed Ptera and Florges as two other of Trova's Pokémon.
I'm probably alone in thinking this, but Trova was such a non-factor this whole series that showcasing Lizardon Y was about all he was ever good for. The battle (the whole round, actually) should have just been a 1-vs.-1 between the two Lizardons so as to allow the Y-variant to get a better showing against X before losing.
Really sucks that Ash won't be using some of his Pokemon from the previous regions. That's what I liked about the Sinnoh League: some old favorites (such as Noctowl, Donphan, Sceptile, Heracross, etc) had the chance to shine.
I was disappointed, too, but the more I think about it, Satoshi's old Pokémon would feel really out-of-place in the Kalos League.
XY and
XY&Z are probably the two most self-contained
Pocket Monsters series, to the point it doesn't even look like we'll be getting the usual appearance from past characters like Iris. DP referenced past series enough that I could buy Satoshi using older Pokémon in Sinnoh, but I honestly couldn't see it here.