Agree. Seems that there is now a strict mode applied to the playgrounds. In this PG, for example, https://www.babylonjs-playground.com/#3RTT8P#9 gives the error assignment to undeclared variable pivotAt, the addition of var to lines 46 and 47 gets it working again.
@PatrickRyan @Deltakosh Strict mode is all well and good if applied from the start, applying it now will mean hundreds of PG will now have the potential to fail.