Pink line in the corner screen of ipad air M2

Your iPad Air M2 has a conventional LCD screen that is edge-lit with a backlight diffuser. In a dark room, with a blank screen, a brightened edge as you illustrate is characteristic of this screen technology.

If you have any concerns, you would be well advised to visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will be able to assess your iPad. If a fault is identified, you'll be in the best possible place to explore your available options:

Genius Bar Reservation and Apple Support Options - Apple

Without a link to precisely what you have read in your research, it is difficult to offer qualified comment. The type of issue to which I think you may refer is characterised by a clear, sharply defined, line of pixels visible at all times regardless of ambient lighting conditions. By contrast, your photo shows a diffuse glow along the edge of the screen, only visible in low light conditions, this being a characteristic of the screen technology used by your iPad Air.

To reiterate, if you have any concerns whatsoever, you would be best advised to visit the Genius Bar at your local Apple Store or Apple Authorised Service Provider (AASP) - where the technicians will assess your iPad screen for defects. If an issue is identified, you'll be in the best place to explore your available options:

Genius Bar Reservation and Apple Support Options - Apple