A compilation pack refers to a collection of things put together, usually various items or materials that are grouped into one package. Full definition
Access Granted is another DLC compilation pack that consists entirely of pre-order bonus content that was available to other versions. (nintendotoday.com)
The downsides however are: There is no Sonic3 & Knuckles lock on feature like with previous compilation packs, that was sadly not added in. (wolfsgamingblog.com)
There have been compilation packs before on the PS2, first X-Box and the Gamecube. (wolfsgamingblog.com)