Quote:...-Does the alpha to selection made it regular layer and not text permanently?..
No. But do not rely on recovering the original text layer, many thing can happen between-times.
The obvious is duplicate the text layer before filling with a gradient and losing the text property.
Another is text to path before filling with a gradient and losing the text property.
However, if it was a Gimp text layer, try selecting the text tool, click in the (was) text layer and you get a message like this.
Choose create new layer and you get this.