I also talked with Berkley. I was told that they are going to phase out the original Fireline. You can still find some on line with the original label. I got a 1500 yd spool of 6 lb from Scheel's.
Their new improved superline will still be called "fireline", There is a slightly different label on the spool. It says thermally fused tough.
New and improved FireLine® is smoother, tougher, and more sensitive! 8-strand fused technology provides unmatched abrasion resistance making it 5X's tougher than conventional braided lines. It has a smoother, more supple feel for a longer casting FireLine®!"https://www.berkley-fishing.com/collections/superline/products/fireline-1292708
To add to the confusion the person a Berkley also said: "There will be a new product that uses fireline and will be called Bead Smith. Same as original fireline but any given pound test will be thicker." I have no idea how Bead Smith can be the considered same as original Fireline yet be thicker for any given pound test.
At least you can still buy the phased out Fireline here and there. And soon there will be a superior replacement for it.