RE: Odd ATC Clearance?
A "side step" approach is a valid procedure (at least in the US... I have used it myself in the real world.) A side step procedure uses the published approach to a parallel runway (usually a precision approach such as ILS,) then allows the pilot to transition to the preferred/requested parllel runway once the runway environment is in sight.
It's a really slick way to use the approach capabilities of a precision runway, but allow the aircraft to land on a preferred runway that either does not have an approved approach, or the approach system is out of service for that runway.
I've even used in visual conditions when parallel traffic has cleared the runway and I asked for side-step to that runway.
Hope this helps.
"I'd rather be flying!"