Spontaneous Escapes is a monthly promotion Singapore Air has been running until the pandemic hit. Travel has since resumed, and so has Spontaneous Escapes after a 2-year hiatus. The promo usually gives a 30% discount (I remember there was once it hit 50% pre-pandemic) off certain flight redemptions made with miles, and this month sees a rather short list of destinations getting this discount. The fewer countries could presumably be due to the fact that the travel dates fall within the June school holiday period which naturally sees an uptick of travel.
You have to book the flight before end of May, and the flight dates must be within June 2022 in order to qualify for the discounted rate. Note that you would not be able to change your flight details, and you will only get a refund if the flights are cancelled by SIA.
You can view the full list of destinations and details here....