Did Criterion loose rights to this one? How is the Second Run disc region free (A/B/C)? I am sure that a little change in title can't allow that. Can "Main" to "High" make the UK release region free? I am just curious.
In my experience (and I produced Arrow's discs of The Firemen's Ball
and Closely Observed Trains
from the same source), rightsholders from this part of the world rarely insist on region-locking.
I suspect it's pretty rare for them to get a title distributed simultaneously on both sides of the Atlantic, so from that perspective there's a stronger argument against region-locking than in favour of it. If I remember rightly, the BFI's Jan Švankmajer package was only region-locked at the behest of one of the non-Czech rightsholders, but I've long since forgotten which one.
Obviously, the slight difference in title is completely irrelevant - the film has always been known as The Shop on the High Street
in the UK, as it's a more colloquial local translation ("Main Street" is such an indelibly American phrase that it's jarring to a native British English speaker when applied to an obviously non-American film). Similarly, although the Czech NFA told me that they'd prefer Czechoslovakia's second Oscar winner to be called Closely Watched Trains
in all English-speaking territories, I sent them a dossier of material demonstrating that both it and the source novel were so well known in the UK as Closely Observed Trains
that changing it now would be needlessly confusing, and they accepted this.