I feel like we all instinctively knew that this relaunch was coming.
Beyond, while a very interesting story on its own, was always meant to be a six-months-or-so stopgap between the end of Nick Spencer's run and the beginning of the next big writer's run.
Spider Man: Beyond ends with The Amazing Spider-Man Vol 5 93, which is ASM 894 in legacy numbering.
I see three options here for what they launch with John Romita Jr. in April:
a) A five-issue event miniseries (LGY 895 - 899) to introduce the new Spider-Man status quo, followed by the ongoing (ASM Vol 6) starting with issue 1 (LGY 900).
b) A six-issue event miniseries (LGY 895 - 900) to introduce the new Spider-Man status quo, followed by the ongoing (ASM Vol 6) starting with issue 1 (LGY 901).
c) The new ongoing, Amazing Spider-Man Vol 6, starting with issue 1 (LGY 895). The sixth issue, also the end of the first arc, will be the milestone issue (LGY 900).
Option (c) is a bit like the John Ridley Black Panther relaunch, where Black Panther (Vol 8) 3 is also milestone issue 200.