Alberta's health minister says the province could soon be announcing an extension of the allowable period between a first and second dose of vaccine, up to as long as 16 weeks.
I think the 'fantastic data' isn't actually about the effectiveness of the 2nd booster waiting that long, it's just all about getting everyone vaccinated as fast as possible.
I would feel much better if there was at least a comparison showing titers of people getting the 2nd dose at 12 weeks vs. 4 weeks. Wait a few weeks after that 2nd dose for it to kick in to take those samples. Maybe it's been done, but no one is really mentioning where to look. It's difficult to narrow search terms enough and it may be unpublished data being shared between governments.