Hi Ayesha, I think it needs a question mark at the end. 'Will will be seeing you soon?'. It is asking if you will meet the people who are asking. It is already a sentence. 'We will be seeing you soon' is an informal way of saying goodbye. It also means that the people will meet you again.

It means will we see you, probably soon. No difference to Will we see you really, maybe a little more informal/friendly but different people might not agree! Will we be seeing you this weekend? Maybe means we've invited you to a party and we are asking if you will come.

The person asking the question wants to know if you will be at an event in the upcoming future.