The word 'significantly' in this case appears in the lead of a one minute long press release, that isn't scientific literature. So it is a bit ambiguous and be

The word 'significantly' in this case appears in the lead of a one minute long press release, that isn't scientific literature. So it is a bit ambiguous and best practice would be to use 'substantial' or similar, because if it is being used to refer to statistical significance and not effect size in the press release it can just be omitted, should be a given that a positive result was significant.