This is a notification that appears as the current BBT trophy is about to end,
and you have teams that have participated during the season.
The Steel Gauntlet is a playoff-tournament that (somewhat simplified) takes place after each season
for the most successful teams for each roster.
In order to have a chance to be accepted into the playoff, you must mark each team willing to accept
a spot as such in the "My Squads" panel of the Blackbox Trophy page. Leaving it undecided (the default)
will eventually count as a decline of a spot should it be offered to the team.
Further details regarding the qualifier system can be found under the Team Standings panel (also
on the Blackbox Trophy page).