Spyderco routinely discontinues many knives each year.
They've already discontinued 12 knives this year and the year isn't even over yet.
They publish an "official list" of the knives that they are discontinuing each year in the Spyderco Forum. The Slysz Bowie was discontinued in 2018 together w/over 40 other knives.
See:
Discontinued For 2018 - Offficial List
I assume they discontinued the Slysz Bowie for the same reason they discontinue so many others, including but not limited to the following:
1) it didn't sell well (enough).
2) there wasn't enough of a profit margin in it
3) they don't want to make any more of them because of 1 & 2 above.
4) it was too expensive/difficult to produce plus 1 & 2 above.
5) it was considered a limited run and they never had any plans to make any more.
That said, they have "resurrected" certain models as Sprint Runs (they're talking about doing that w/the Ayood again now; this would be the 2nd Ayoob Sprint) and, as is already the case for the Slyze Bowie, they can produce an Exclusive variation of the knife, if there's dealer who is willing to pay in advance for its production and bear the entire financial responsibilty/risk for selling it.
Spyderco could still release a Sprint variation of the Slysz Bowie but, of course, no one knows if/when that might happen and, if they do, it will NOT be an exact replica of the original.
The only way to get an original is to buy it on the 2ndary market or, if you want one that looks like the original (but really isn't), you could buy the current Exclusive (for about 1/2 the price of what ppl are asking for the original now) and de-annodize it w/HCl.
There are OTC products that you can buy at Home Depot that has HCl in it which ppl use for this purpose.
As far as I can tell, the only difference between the original and the Exclusive is the color and the blade steel.
Looks like the original dies were use to form the frame. So, if you de-annodize the Exclusive you'll have a Slyze Bowie look-alike w/an M390 blade which IMO is better than the CTS-XHP in the original.
I've thought about doing this myself but I don't want a Slyz Bowie bad enough to spend $400-500 for the Exclusive (which is what it's been going for here on the Exchange) and then go to the trouble of de-annodizing it.
PiterM
posted above becomes available, I'll be buying two or perhaps three. Call me a fool, but it's love, I tell ya, love. 
