I still don't get this.
If it is true, it is ridiculous.
A player should just have to notify the ATP when he retires. It is a job, right? This is what people do with jobs? No need to read every interview. Just submit a piece of paper.
He is taking opportunities away from other players who need opportunities.
Why the consternation? It's not like this is the first time it's happened. We've seen it several times in the past. People announce retirement and linger around somewhere in the rankings for most of the next 12 months. Edberg did it, for one, and he was much higher ranked at the time of his retirement. He announced end of season 1996 would be his last match and never played in 1997. Still he was ranked in the top-100 until September 8th 1997 and the top-300 until November 3rd. And he advanced in the rankings on five separate occasions that year.
Ranking system tells us how many points you've taken in the last 12 months. You only get taken out if you specifically ask to be taken out. Not everyone do that. You are free to feel they should, to make the rankings more actual, but it's their prerogative not to if they'd rather watch their name slipping downwards a few months.