"Interesting"...but the article kind of makes eyes roll in some ways.
One of the submarines I served aboard was a SpecOps boat...the USS L. Mendel Rivers (SSN-686). She was modified to be capable of carrying a Dry Deck Shelter (DDS) topside, which housed a small submersible which SEAL teams could deploy to and from the boat while submerged.
Those SEAL guys were awesome, too, by the way.
On the general subject of what firearms they carried...the short answer was "whatever they considered necessary for their missions". In other words, if they believed any given sidearm, rifle, assault rifle, automatic weapon was necessary, then they got it.
And they trained with pretty much anything as a result, in order to be proficient with mission required equipment.
SpecOps budgets for these matters, while not "blank checks", allowed for exactly this. (Not saying this is identical across all the branches.)
So the article title stating "How the U.S. Military Slowly Fell in Love with Glock" is misleading. We're talking about very small, exceedingly elite, SpecOps communities. Not the military overall. And their reasons for obtaining any of the weapons they (SpecOps) required do not necessarily mesh with the overall Military desires/requirements. You can't really mix and match "military overall" with "SpecOps" this way. You most certainly cannot align the general military wide sidearm criteria in totality with that of the SpecOps communities.
Glock lost out to the SIG Saur P320 through a pretty minor scoring issue, centered around the modularity scores. Had the Glock entry scored higher in that one category, relative to the other entries in the competition, it very likely could have come out on top over the P320. They did, in fact, "make it to the finals" in that competition.
By any measure, the Glock is a fine, even outstanding, sidearm. In the highly competitive firearms industry, for a company to come up with a competitive pistol design in the 1980s and become as successful as they have become in such a short time says a lot about their quality and reliability. You DON'T break into an established market, take it by storm essentially over night, and maintain that kind of performance history by making a POS firearm.
(They're still ugly as sin, though.)
SO...WHAT ABOUT THE FUTURE?
At some point in the future, the military is going to once again re-evaluate the need for a new, general issue side arm. When this will happen will likely center around a couple things:
1. The current material status of the (then) existing stock of general issue sidearms (the P320).
2. The duration of the contract and the support provided by that contract for the existing general sidearm (P320).
When they reach that point, they will put out for bid entries for the next sidearm competition.
And you can bet Glock has already taken a good, hard look at how they were rated in this last competition and have already considered ways of improving their scores for a future competition.
REGARDLESS OF WHETHER GLOCK WINS THE NEXT COMPETITION...one thing will remain constant. There will be a huge deal made out of nothing much at all because in the end, the sidearm is the singular, most underpowered and undercapable firearm any servicemember will ever carry.
Not to say it's "useless"...just that too many people place too much credence/importance in the military sidearm. It's just a pistol.