The phrase "previous gen" refers to something that belongs to the previous generation or version of a particular thing, usually in terms of technology. Full definition
Disappointing, but well, that's mainly MS fault that they fucked up end of previous gen and beginning of current gen. (neogaf.com)
#WWE2K18 on #NintendoSwitch is not based on previous gen versions. (thisgengaming.com)
If you could win in the U.S... you're gonna dominate the console industry, just like how the PS2 and The Wii, dominated in previous gens. (nintendotoday.com)