Frustrate your opponent to death

Frustrating your opponent is always the goal of Tempo, and what's more frustrating than countermagic? We have Quench to control the early game, Negate and Sinister Sabotage for counter magic that can go later than Quench, and Thassa's Intervention which gets better as the game goes on (and can also help you dig for the cards you need to survive a turn or close the game). Brazen Borrower gives you additional options with bounce.

But those are all the normal blue frustrating cards. What about frustrating cards in white? Azorius Tempo seeks to leverage Staggering Insight to frustrate our opponent via quickly insurmountable card advantage:

Probably the best white card for tempo in current Standard - the ability to draw an additional card every turn is game winning (not to mention the lifelink against Mono Red), and this card advantage is what made Mono Blue Tempo so powerful in the last block with Curious Obsession. However, Staggering Insight must be protected and we lost many good cards to help us do that cheaply, like Siren Stormtamer, Dive Down, and Spell Pierce. However white did gain a couple of notable cards for consideration in tempo:

Alseid, like Siren Stormtamer, can be sacrificed to protect one of your creatures from removal. It can also be used to absorb a lot of damage (particulalry powerful against Embercleave decks), or to make one of your big creatures unblockable if your opponent's creatures all share a color. This means that unlike Siren Stormtamer, Alseid is also a good top deck to help you finish games, and it should not be understated how relevant that is in tempo when you are running cards like Brineborn Cutthroat and Nadir Kraken which can grow to be giant threats and whose biggest downsides are a lack of evasion.

Gods Willing is the other big protection card we've gained since rotation which can do the same work as Alseid at a slightly cheaper cost: either protect a creature or make it unblockable for the win.

Big Threats that Need Protecting

We honestly don't have a perfect replacement for Tempest Djinn. In blue, Nadir Kraken and especially Brineborn Cutthroat are pretty good, but they lack the evasion which was a huge part of what made Tempest Djinn so dang good. Luckily, Alseid and God's Willing can help us there by making our threats unblockable. We'd honestly like to play Archon of Sun's Grace and run a few more enchantments like Omen of the Sea, but running a double pipped white card is very hard to do with the lands we have currently available in standard - this deck cares A LOT about having untapped lands in the early game. Without untapped lands on turns 2 and 3 we miss out on some of our best counterspell targets in the current meta and/or on our opportunity to put down a Brineborn Cuthroat on our opponent's turn 2 and hold up protection for it on turn 3. Tapped lands are particularly bad in Tempo when you are on the draw. I believe there is a viable version of Azorius Tempo which can run Archon of Sun's Grace, but it has more lands which come into play tapped in order to help color fix and so it makes less opening hands keepable since you cannot reliably Quench, Negate, or Sinister Sabotage when you need to, especially when you are on the draw. Because Tempo is already very susceptible to variability in the opening hand, I went with Nadir Kraken instead for this list, but I could see this changing if we get better aggressive lands in future sets.

Sideboard

A variety of counterspells for different matchups is good, especially because our mainboard is fairly light on counterspells for a tempo list. Teferi, Time Raveler against control mirrors, flash decks, and Reclamation decks. Glass Casket against aggro when you need cheap removal for creatures or exile for Phoenix of Ash, Uro, Titan of Nature's Wrath or Kroxa, Titan of Death's Hunger. There's also some color hate with Aether Gust and Cerulean Drake.