Short answer: the original is not back, and it is not coming back. Its domains were handed to IFPI as part of the 2019 settlement. This site is a new, separate tool that uses the familiar name.
When convert2mp3.net shut down in June 2019, the settlement required its domain names to be transferred to IFPI. A site cannot come back when someone else owns its name. Any page claiming to be the resurrected original is misleading you.
Full history: what happened to Convert2MP3.
A new converter, built from scratch, that adopted the well-known name. It converts YouTube links to MP3 in the browser: try it here. It is not affiliated with the old operator.
Dozens of sites use the Convert2MP3 name. Some are harmless converters; others are ad traps or worse. Red flags:
More: Convert2MP3 clone sites.
The original is gone permanently. This is a new, separate tool.
The original's domains belong to IFPI. Any working converter with the name is a different operator.