Much like every year, a number of NXT stars have joined the main roster after WrestleMania. Two former NXT Women's Champions, Roxanne Perez and Giulia, have transitioned to the main roster. They were already traveling to the main roster before WrestleMania 41, and their main roster move was pretty much imminent.
Both of these wrestlers have done a tremendous job in the NXT, which is the developmental territory of WWE. Both of them had been former NXT Women's Champions, and clearly, both of these wrestlers have bright futures waiting for them in the main roster.

It is a terrible decision to keep Roxanne Perez and Giulia in two different brands
When the duo started working in the main roster, they were shown as a team. They were having a fluid with former three times Women's World Champion Rhea Ripley, and they kept on making the life of the Australian professional wrestler miserable.
Roxanne Perez and Giulia started their main roster journey as a team
They were being portrayed as an amazing team, and fans loved seeing to see them together. They were certainly the best heel team you know the women's division of WWE. But suddenly WWE decided to split this team as Giulia went to SmackDown and Roxanne Perez stayed on RAW.

Perez stayed on RAW, and Giulia went to SmackDown
If there is any division in WWE that is doing worse than anything else, that is the Women's Tag Team division. It has been the weakest part of the promotion since day 1, and they never even tried properly to fix the issues. Every time a good team was built, they either split it or did not continue it.
CM Punk to leave WWE? Check out the exciting details here
Roxanne Perez and Giulia would have been an amazing Tag Team during their initial days in WWE's main roster, and since they are new in the main roster, it would have given a great boost to both of their careers. The Tag Team division would have benefited too. But unfortunately, it looks like they really do not care about the Tag Team division much.