Finding meaning in "height to highest occupiable floor" makes some horse-sense when considering overall height, but I've always found the hardline distinction between "height to architectural top" and "height to tip" to be dogmatic and pedantic silliness.
To me, the Pru is just over 900' (907, "officially"). If folks want to agree that it tops out at 749' that's, of course, fine. I just think the criteria is more than a little arbitrary.
As a litmus test, for those who are firmly in the "Standard height" camp (749'), here's a litmus test: next time you have friends or family visiting who are not familiar with Boston and/or don't really obsess particularly over architectural details such as "accepted heights" of towers within the community, ask them -- when, say, across the Charles and looking at the High Spine, which they consider to be the taller building, the JHT or the Pru. I've done this a handful of times (or something similar) and not once has anyone ever selected the Hacock, or even had much of an internal mental debate before responding that the Prudential is taller.
I've expressed similar before and plenty disagree -- which, again: fine -- but, to me, the spire that they added to One World Trade Center/Freedom Tower is an even more... suspect, or "cheating" way to achieve on-record height that is acceptable to the arbiters of these things than counting the Pru's broadcast antenna. That the Pru's antenna is actually functional, rather than purely decorative to bolster the Freedom Tower's height to 1776', makes it (to me) even *more* fair-game to consider when determining its height.
If the Pru is 749' then (to me) One World Trade Center tops out at 1,368'.
All that having been said, if adding a cage or whatever would satisfy... whoever needs to be satisfied about such things for it to e considered truly to be 907', then sure. Why not I guess? I don't really see the point, but it could look neat.