Waitlisted and asked to share other offers I am considering

[Multiple_Realisms]

Hello, 

I got an email on March 8 from my top choice program I applied to for a studio art MFA informing me that I am on the waitlist. In their email they did not give specific information about the waitlist (e.g., how many people waitlisted, if it is ranked, etc.), but they said I could ask follow-up questions, which I plan to. 

The person who sent the email said that if I am considering other offers, to reach out to them (the program that waitlisted me) so that we can discuss "my options at the (program that waitlisted me)". 

My question is, how detailed should I be in the information I share with them about other offers I might be considering? Do I send documentation of other offer letters/scholarship offers? Or simply say something like "yes, I am considering other programs but am still interested in yours..."? 

I do have an offer of admission with a 3-year scholarship that I deferred from last year, and I already feel bad at the thought of changing my mind about it, but I think the program that waitlisted me has more opportunities for artistic community, especially in terms of the city it is in. I would definitely want to inform that program (that offered me a scholarship) before April 15 if I decide not to go, so I don't further inconvenience them. Should I tell the waitlist program that I need to hear by then? Or is that too pushy? 

Any advice would be appreciated. Thanks in advance.