[savedfrommyspokes]

Brock appeared in the 1980 Topps set on a Highlights card commemorating both his and Yaz's 3000th hits.

In feel that in many of the cases in which retired stars of the 70s were being left out of Topps sets following their last season, Topps did this because they prepared their sets to showcase the players who would likely be on the team for the upcoming season, not as much as for a recap of who was on the team from the previous season (as the stats on the back would indicate). So Topps likely felt that if they knew that a player would not be playing the upcoming season, they could replace him in the set with a player who would likely be on the team for the upcoming season.

The same would apply for players who changed teams....showing the player with the new team ASAP was clearly part of Topps' business plan...they even expanded their offerings in the 80s with their Traded Sets(after some attempts in the mid 70s).