You can find it here:
https://www.ubisoft.com/en-gb/game/rainbow-six/siege/news-updates/2D4HsYOBEEg0wEW5dim34o
Here are my thoughts... starting from the win-delta graphs.
On PC, we can clearly see a rise in Ash's popularity. This is most likely caused by Mira having a high win-rate ratio (4th highest winrate operator), though I don't believe there's a complete correlation between the two. The most picked attack operators (Ash, Ace, Buck, Dokkaebi, and Finka) are extremely easy to play with.
Now, these operators are indeed very strong, especially Dokkaebi, but generally, ranked players tend to lean towards easier or lazier approaches rather than playing operators like Capitao, Montagne, Deimos, and Sens that require pre-planning rather than simply holding down two buttons (sometimes even one).
On the other hand, we can observe a similar trend with "set and forget" utility here. Lesion, Doc, and Fenrir are the three most picked operators (when Fenrir is not banned). Solis requires a bit of work but is still extremely friendly for a lazy playstyle, and then we have Azami and Valkyrie, which are simply strong and straightforward.
BALANCE-WISE
Azami:
She received an additional nerf, but it's not sufficient; attackers can still easily destroy her barriers while shooting. This nerf is beneficial for competitive play, especially considering the prevalence of operators with DMRs (such as Lion, Dokkaebi, Twitch, ...). Overall, I would appreciate it if Azami was reworked by either reducing the number of gadgets or ensuring her barriers form perfect shapes to eliminate pixel-angles or other one-way angles that Azami and her team can use. Another suggestion is to limit Azami to carrying only one kiba at a time, preventing her from stacking for late-round use.
Lesion:
The nerf to his Gu mines isn't significant; he can still use at least 4 mines before attackers get in the building. The issue with Lesion is that he remains a one-man army; even if the impact is removed for an observation blocker, it won't make him a less appealing pick. The observation blocker might even encourage more aggressive play, or a bulletproof camera can serve the same purpose.
Nokk:
The change won't have any significant impact.
Oryx:
The change won't have any significant impact.
Sens:
As a high-skill operator, Sens has always been extremely useful, even before receiving frag grenades, and now, even more so. Most of my students who went further into strat-making understand why Sens is exceptionally powerful.
Impact grenades:
Honestly, who asked? It's yet another buff to shields, and we've already seen a considerable number of shield picks in both competitive and ranked play.