Hello Network
Yes, by default, BGP assigns the weight value of 32768 to all locally advertised prefixes. Those are prefixes that are generated using the network or aggregate-address commands, or via route redistribution. The default weight for learned routes (from BGP neighbors) is 0.
Why is this? Well, remember that weight is only locally significant. Routes with a higher weight value take precedence when multiple routes to the same destination exist. It is always preferable therefore to prefer those routes generated locally rather than those learned from other BGP routers. This is further described in this Cisco documentation:
I hope this has been helpful!
Laz