I strongly doubt whether Tamim or any other National player will be allowed to play - or even be able to go.
I have no idea where this 'report' originates but with a BD tour to Zimbabwe LEAVING towards the middle to end of July, national training camps preparing the players for Test matches before that, and fitness regimes being implemented from June 1st by Grant Luden, it's just a non-starter, IMO.
Can you imagine any player getting injured at a 'made up' SLCT20 before the biggest 7 months in BD cricket with 5 series (Test and ODIs) being planned against Zim, WI, Eng, Pak and SL?
However, with the ZIM series as a priority in less than 40 odd days, you can work it out for yourself.
Ever the optimist