I hadn't heard that, but what is true in the UK is that the TBO is by hours usage and time - for the IO-540 in my Saratoga it is 2,000hrs or 12 years (plus 20% at the discretion of the maintenance outfit you use) so 14.4 years or 2,400hrs. Within this time the aircraft can be used on an AOC and for public transport work. After this, it is on what equates to the old private cat C of A, so no rentals, etc.
As for no IFR, i hadn't heard that one!