Not by a long shot.
Think about the components of the Fick equation:
VO2 = HR x SV x A-vO2diff
The latter increases rapidly with the transition from rest to low-to-moderate intensity exercise, but is already quite wide at even 50% of VO2max. After that, the only way for VO2 to still double (to 100% of VO2max) is for HR x SV - that is, cardiac output - to increase substantially.
It therefore follows mathematically that if your HR increases significantly once you’ve you’ve reached VO2max, then your SV must be decreasing to the same degree. During an incremental exercise test that only happens in clinical conditions, and not in healthy persons. (Note that we are not talking about changes in SV across intensities, or over longer periods of time, during which thermal stress can lead to significant cardiac drift.)
If HR continued to increase by 12 bpm during the last minute or so of a VO2max test in an ostensibly healthy athlete, I’d be looking very carefully at the data to make sure it isn’t a technical issue.
For example, you might see that pattern if the power output is incremented very rapidly, and the metabolic system is abnormally slow to respond (in which case VO2max has been underestimated). There are also systems out there that fail to accurately measure ventilation at high flow rates, again resulting in errors in VO2 and an apparent disconnect between VO2max and max HR.