Not so much advertising as promoting, IMHO. Advertising would indicate something for sale
Asides . . . Lost Alpha will more than likely be the mod that will draw a lot of attention back to STALKER. The mod is intended to be as close to what GSC had initialled promised back in the early 2000s - large, open locations and a gaming world. Many features that were cut and disabled for Shadow of Chernobyl have been reactivated or made to work properly. It's probably the most anticipated mod within the STALKER modding community.
Helping to bring further attention to the STALKER community as a whole, especially with GSC having been paying close attention to the community over the last few months since they've confirmed STALKER 2 is WIP.