Microtransactions in Overwatch 2 are summarized as...
Overwatch 2 is a free-to-play game. The main monetization of the game is the purchase of cosmetics using a premium currency.
Overwatch 2 is technically a new game, but everything from Overwatch 1 will carry over, including cosmetics currencies.
The store features 2 primary ways of purchasing cosmetics using the premium currency. The first is through an always rotating limited time store. This store features nothing but bundles and each item can not be obtained individually. Items in this store are often on sale with a discount percentage even though these items can not be obtained otherwise, this practice is illegal in many countries.
The second way of purchasing cosmetics is through skins that are always available in the hero gallery. Most of these skins were available for free in Overwatch 1 through the use of in-game earned Credits. The credits you have earned in Overwatch 1 are still available in Overwatch 2 but there is no way to obtain new credits. So if you run out or if you if you never played Overwatch 1 the only way to purchase these cosmetics is through the premium currency. The cost of cosmetics for Credits is vastly increased in comparison to Overwatch 1. Many types of cosmetics are 2 or even 4 times more expensive in Overwatch 2.
The premium currency can be obtained for free through weekly and season challenges. The rate at which you earn these is incredibly slow. Earning enough for a single legendary tier skin will take you close to a year if you complete all challenges. Take it as a free sample designed to lure you in to spending more.
The game features another currency called "Overwatch League Tokens". These can be obtained for free by watching the Overwatch League eSports streams. Alternatively you can purchase these tokens with real money. The price of both the tokens and the cosmetics has increased dramatically as compared to Overwatch 1, even for skins that are not new to Overwatch 2.
Overwatch 2 features a Battle Pass. This Battle Pass has a free track, but the items earned from this track are generally low quality. The Battle Pass does not earn any Premium Currency, and thus if you want each Battle Pass you will need to purchase all of them separately. A Battle Pass lasts roughly 2 months, so this will come out to roughly $60 a year.
Battle Pass levels can be purchased using real money to speed up your progress.
Some characters are locked behind a tier far into the Battle Pass, which is also available on the free track. It will require significant time investment to unlock these characters.
The Battle Pass is time limited, if you do not finish it in time you do not get what you paid for. In this case that also means you will not unlock the character.
If you wish to unlocked characters from a previous season you will need to complete a challenge. This challenge will involve winning a large amount of games playing a specific role. This can easily take several weeks or even several months of play for the more casual player base. Or you can spend money to unlock them instantly.
The Beta for Overwatch 2 featured a pre-order bonus that got you in to the beta instantly. Otherwise the only way to get in was to sign up and hope you got lucky.
On top of that Overwatch 2 features PvE missions, but to play them you need to buy a bundle that costs $15. This bundle contains some other content, such as character skins, but it's the only way to purchase access to the PvE even if you do not care for the other content.
Overwatch 2 is a very expensive game and will require significant time and monetary investment if you wish to unlock cosmetic items, as well as playable characters going forward.