Part exchange property

[az33]

Hi,
First time buyer here so pls be kind :)
There is a property we are interested in and they told us is being part-exchanged with a property developer and the owner will move when the development is ready, apparently April.
We of course know that this might then mean further delays, ie if the property is not ready then they can't move. Is there anything else to look out for, ie is this a risky transaction, or similar to long chains?
To be honest we wanted to move by April at the latest, as we are in the position to, and slightly put off by this scenario that we are not familiar with. Anyone that has been in the same situation and can advise, maybe even about any questions to ask?

Are you sure they said part exchange? A part exchange usually means the seller is selling it directly to the developer, not to a private party.

Or do you mean you're buying it from the developer once they've bought it from the people who currently live there?

Yes that's what the estate agent said.

It's confusing as it's the current owner showing the property.