When you have Pfizer, Moderna, Sputnik V recording low to mid-90% efficacy then there has to be a pressure on others to report their results as being as successful as that. That's just common sense.
The issue with the Oxford vaccine for me was less the claimed immunity than the demographics of their testing population - an issue for scientists who looked at their data. Hopefully assurances can now be given along those lines - that older groups have been more widely tested and they respond similar to younger groups to their vaccine.