I think the main reason why they killed off the Explorer and GT was so there weren't a cluster of similar priced machines competing with each other for pretty much the same customers that would then otherwise just buy an Etrac if no other choices in that near price range were available.
This makes perfect business sense, even if some of us don't like it. Now there is clear distinction between the CTX, the Etrac, the Safari, & the Xterra line, as far as price/performance goes, and so you aren't spending X amount of dollars to build machines competing in many ways (price/performance) for the same customers you'd get otherwise with a more slimmed down line up.
That's MO anyway, and if that bares out then I doubt they'll make yet another machine to replace them that will once again clutter the price/performance line up aspects in relation to the Etrac and other steps down/up in model prices. Just wouldn't make sense to re-do what you just un-done. I would suspect it would be a very big possibility for a land/water unit in the $1000 price range to kill two birds with one stone, IF they had also canned the Excalibur. Then it would make perfect sense- one machine to do what the GT and Excalibur both did, and at 1/2 the manufacturing cost of two machines together filling the same dual land/water purpose.
What I really would have liked to see them do, was to eliminate the Safari and then price the SE at roughly under $1000 a hair. Then enough price distinction would exist between the Etrac and SE so as not to compete for the same customers. Both are very different machines in respects of things like the VDI setup scale. To me it's a Ford Vs Chevy thing in terms of which people pick of the two. I'm an Explorer guy myself having owned or used both.
Another option that I would have thought would have made more sense to me, would have been to eliminate the Safari and then price the GT in say the $750 or so price range. It's different enough from the FBS units so as not to compete with them for the same customers, as some prefer analog style controls on a detector and the long analog-like audio in certain respects. Just look at how some machines have a rabid following of users due to analog controls for that reason alone, and how even Whites put analog dials for some functions on there M6/MXT computer screen detectors.
Regardless, no sense of crying over spilled milk. My biggest advice to those who want one, is to get an SE or a GT order in before the December deadline, or the 8" or 10" Tornado coils in the GT's case which are also being canned and are already very hard to find used due to how good they are. After that you might find a dealer with one in stock for say the next year or so, and then it'll be the used market only, which I suspect is going to be rather hard to find one of these two machines through, at least at a reasonable price.
By the way, isn't the warranty now 3 years on a Minelab? If that's the case then say a dealer sells a SE or GT a year from now he still had in stock. That means at least 4 years out of repair service, and I would suspect many years to come after that, because it wouldn't look very good if you couldn't get a machine fixed as soon as the warranty expired. For that reason I wouldn't worry about getting either one fixed down the road for some time out.