Libero IDE v2.3 converts your v2.0 and v2.1 *v(hd) and *.sdf files to include the “_ba” identifier. When selecting a these files in the File Manager, a warning “The %file was added to the project” appears to let you know that the file has been converted to the new naming convention.
This is due to a naming convention for back-annotated files that started with Libero IDE v2.2. Libero IDE only recognizes back-annotated files that contain "_ba" as part of the file name. Starting with Libero IDE 2.2, when you export files post-layout, Designer exports <top>_ba.vhd and <top>_ba.sdf to the Libero project. These files appear in the Libero File Manager, under Implementation files. The "_ba" is added to the file name by Libero IDE to identify these files for back-annotation purposes. <top> is the top root name. Pre-layout exported files do not contain "_ba" and are exported simply as *.vhd and *.sdf.