“Mayak will stay on orbit for one month. After termination of term of use it will be deorbited and burnt in the atmosphere.”
That was on their website. I take that to mean it will exist as a simple cubesat for a while (a month?) and it will collect data. Then when that mission is achieved it will deploy the sail to deorbit. I imagine a month also gives them a chance to get a good handle on how the orbit would decay without the sail, so that after deployment the change becomes more apparent.
Cubesats can be pretty dim so an up to date TLE, good pointing accuracy and a GPS system setting your system clock are essentials for a tracking system.