No. Text layers are special animals because as long as they aren't subject to any modification outside the Text tool Gimp keeps them as vectors and retains the text information (font, size, spacing, kerning...). But as soon as something changes outside of the text tool they are converted to bitmap(*).
Btw, rotating a text layer is usually a bad idea because rotation of a bitmap implies an interpolation of pixels which results in blurred edges. A better technique to keep sharp edges is to:
- Keep your text layer as a text layer (which solves part of your problem)
Layer>Text to path to generate a path from your layer
- Apply the transform tool to the path (all transform tools have a
Transform: option to make them apply to the current layer (default), the selection mask, or the active path).
- Get a selection from the path (
Select>From path) and bucket-fill it on a new layer
(*) I admit that transform tools ought to be able to keep them as text, though....
Edit for Gimp 2.10: In Gimp 2.10 the text tool can create vertical text (which is the most frequent use case of text rotation). This rotated text is of course editable.