CD Projekt Red endeared themselves with The Witcher 3 expansions and DLC plan and they are looking to continue the good streak with Cyberpunk 2077 which will apparently have the same amount or more additional content.
CD Projekt held a teleconference regarding the earnings in 2019 with the investors where a lot of interesting info was revealed. Besides The Witcher 3 sales over the years and CP2077 numbers, they also revealed a portion of the expansion and DLC plan for the latter.
According to Adam Kiciński, Cyberpunk 2077 will have "no less DLC than The Witcher 3 had". Considering that expansions are mostly counted as DLC these days, we could be looking at at least two expansions with fully-fledged storylines, just like with Hearts of Stone and Blood and Wine.
There are two major things to keep in mind though. The first one is that Kiciński did not specifically say "expansion" and the exact word was "DLC", this is still not a 100% confirmation on the expansion scale. Secondly, and possibly the better part is that "no less than The Witcher 3" statement, meaning we could be in for more than two expansions.
Additionally, The Witcher 3 had plethora of DLC drops that weren't expansions during its lifetime. The best part is that these weren't paid and included gear, cosmetics and even new quests. With that in mind, it seems like we will get something along those lines in CP2077 as well.
Finally, Kiciński noted that the DLC announcements will happen in "a similar scenario to The Witcher 3", meaning we are likely to get the official information about DLC and expansions months ahead of Cyberpunk 2077's release. This was the case with The Witcher 3 reveals, after all.
Before that happens, however, keep in mind that extrapolating info from a single sentence is not an exact science. In other words, there might be slight deviations from the predictions.