All the HP/defense changes!! (maybe)
This source details all the meaningful pokemon and what their changes will be. We don't know how accurate this is but i would wager it is somewhat representative of the future balance changes. It fits in with Niantics plan to narrow the gap between low and high defense/HP
https://www.reddit.com/r/TheSilphRoad/comments/9n3qz7/speculation_how_the_new_cptankiness_ranking_could/
Notes;
-Blissey is finished. It loses near half its bulk. Snorlax loses loads aswell.
-Gengar becomes about 20% more durable, which means it can tank an extra confusion off Mewtwo!!
-As does Breloom, making it a more viable alternative to Machamp. Hariyama is nerfed and is no longer the second best fighting pokemon.
-Machamp is virtually unchanged
-Rhyperior is a big loser. It will now be a marginally better version of the current Rhydon (which will also be nerfed) not quite the powerfouse it was forecast to be.
-Vaporeon loses about 25% bulk. To think it was once the games powerhouse..
-Another former GO king Lapras also loses further bulk
-Groudon and Kyogre both lose some bulk. Rayquaza and Mewtwo also lose some though not as much as the former two.
-Ho-Oh loses about 20% bulk. Such a big loss that Niantic should consider removing the 9% nerf from its stats
-Raikou loses its advantage over Zapdos
-Garchomps bulk is reduced to Dragonite levels
-All the deoxys get a 40% bulk increase. Deoxys normal now has more potential as a glass cannon (if it had a proper moveset.) The others are still pretty useless.
Answers
I know in the internet generation there's a tendency to believe anything that's online. Recently facebook has been spammed with posts saying ladybirds are carrying STDs (no joke.) People actually believe this amusing nonsense, and they might set out to kill said ladybirds, all because of some fake news :(
I'm not responsible for people who take things so literally. However i'm sure other people are interested in what the potential buffs/nerfs are, even though no one knows for sure yet.
If you read the followup link and the comments on the follow up link I think the user Sadyc criticism was pretty close.
It's very possible that Blissey GAINS hps. That all pokemon gain hps. But because in main series hps arent just stamina*2 like they are in PMG they are +Level +10.
This means every level 40 pokemon would gain 50 hps. The balancing part comes from the fact that Blissey gaining 50 is only a 15%ish gain, while Alkazam gaining 50 would be a 50% gain.
Blissey's nerf would likely come from the rebalancing of Defense Stat. Defense is a combo of Defense & Special Defense. But it takes 7/8 of higher, and 1/8 of lower. This gives a huge advantage to pokemon with a big spread of Def/Special Def ala Blissey.
So even though Blissey gain 50 hps, it will be at least as easy, or even easier to beat then it is now.
In grand scheme of things though, it means that pokemon will at best keep defense same, and that almost all pokemon will lose bulk.
If a pokemon's defense and special defense are close together the extra 50 hps would add bulk. Meganium for example has same SD/D in main series so it would get boosted by a better conversion.
Blissy is going to lose bulk for sure, since it's spread is one of the largest in game.
A pokemon like Meganium will have no change to its defense. In real terms this is a buff, since any pokemon that does have a spread is going to go down.
Niantic have said "most pokemon" will lose some defense, so the theory that they'll achieve this by taking more account of spreads between def/sp defense makes sense.
In GO Blissey has at over double the durability of nearly every other pokemon, yet it's not even the most durable pokemon in the main games. A good example of how Niantics CP formula is flawed
Well it is very durable if u attack it with SA in main game.. but who does that?
My guess is blissey will still be the bulkiest pokemon, but not by as much.
Also if you follow the links it talks a lot too about the fact that pokemon in go don't do as much damage as they do in main series, further increasing bulk gaps.
you're seeing the half empty glass of water, the nerf to the bulkiest monsters, but what of the squishiest monsters like alakazam, gengar, gardevoir, etc etc? they gain bulk so they can be used more time to make damage, a lot of damage. By the way, there are more monsters in the lower end of bulk than in the upper end, so in the end more than a nerf is a good way to balance things.