Yea,...that doesn't make much sense. Better to have some excess from a newly-built power source first,...then,...begin slowing down and then shutting down the older source. You can't leave "gaps" like that,...very irresponsible.
Another example in my area in Michigan. We have this oil and gas pipeline that runs from Canada, south into the upper peninsula of Michigan, then goes under the Straits of Mackinaw, into the lower peninsula of Michigan. It supplies 10's of thousands of customers. Well, it's been there for decades, and every now and then a huge cargo freighter might hit the pipeline with an anchor or whatever,...a very real risk of a "biblical" type natural disaster in the Great Lakes. The Great Lakes are the largest reservoir of fresh water in North America. Legitimately, there has been this huge political push to have this Canadian company shut down that old pipeline. Of course,...the question is,..."and replace it with what?" You have to have all of those customers hooked up to a new power source first. This has been going on for the past 5-6 years,...and still nothing has been done except to have the pipeline covered and reinforced under the water. These idiots STILL do not have an alternate plan for these customers.
It's things like this that give me little to no trust in "big electric" and "big oil". At one time we used to have clean drinking water supplying our homes,...well, it's "clean",...but full of trace chemicals you wouldn't water your plants with or feed your pets with. My next home will use solar condensers for pure drinking water,...I don't trust the utilities anymore.