That depends..

On the supply, energy, cost or limitations of a BC.

For example, they could make them take like 20 supply, consume all energy on jump, stay frozen 20-30 seconds after jump, make them cost 1000/1000, 5 mins build time or simply make their number limited (like the Protoss can only have one mothership, allow only 4 battlecruisers) and many many other little features that can detriment their advantage.

I guess they'll test them out and apply patches to keep (or recreate) the balance. One could argue that a build focused on BC's would lose to early and mid-game aggresion asap, so it's hard to know how big their advantage would be with that jump ability :)