Originally Posted by pptskyy

I assume OP refers to a codeshare flight marketed by SK and operated by SQ, to fly end of this year. If SK were to leave *A by that time, then it is likely that SQ may not wish to credit to their program for a SK-marketed flight and SK may likely wish not to credit that flight to EB either, as it is operated by another airline which is not in the same alliance any more. For that reason, if getting the miles is a goal, it may be better to book from SQ directly or if there is another codeshare within *A that could be fine also. My BT analogy is not precise indeed and, in my case there was a BT flight number as well as LH.