Borderlands 2 received 4 story DLCs in it’s first year up until June-July with the Tiny Tina DLC, same as the first season pass of Borderlands 3 with it’s 4 story DLCs.
Then they did a couple of short DLCs called “Headhunters” that were about 30-40 minutes long and there were 5 of them (so about as long as the Krieg/Bounty of Blood DLC all put together) for 3 dollars a piece in it’s second year that ended in April, once again around the same time this Season Pass 2 content has ended.
Then they did basically nothing until around 2015 were they did a couple of balance changes were they buffed some skills and weapons like Maya’s Acid Cloud or the Fastball, IIRC. Nothing happened then until two years ago when they released DLC5 (Commander Lilith).
TL;DR Borderlands 2 got 4 story DLCs in it’s first year, 5 short DLCs called Headhunters in it’s second, a balance patch in it’s third year and then nothing until a new DLC seven years later to hype up Borderlands 3.
I’m pretty sure 1 or 2 patches for BL3 are still in the pipeline since there are 2 Vault Cards missing. Whether Gearbox introduces crossplay/rebalances some stuff/adds more endgame besides that or even does a free DLC that leads up to BL4 like they did with BL2 is up to them.