So Rolex has been pissing off watchmakers for the past six months by basically denying Rolex parts to authorized repair centers, in some cases abruptly ending relationships with 20- and 30-year histories. This is because Rolex is consolidating their repair into authorized service centers.
This move is effectively an extension of that - mod your Rolex and it's no longer a Rolex and nobody can fix it for you because nobody can get parts. Rolex, after all, has stated that a Rolex with one non-Rolex part is not a Rolex.