Going with this pressure cooker, made of aluminum, 15" diameter, 12" tall. I'm giving this a similar thickness throughout. At 8.4# weight, that leads to 0.094" thick.
Applying Roark's 7th edition, Table 15.2, Case 20, using the approximation listed, formula, the 0.094" thick shell can withstand 82 psi of external pressure without buckling. Even with comfortable safety factors in place, this seems plausible. Only when the shell gets really thin (I calculate 0.05", or anything lighter than 16 gauge for this particular pressure cooker) would the shell buckle.
Note that since the bottom is flat (i.e. shell with infinite radius), then if it can handle 15 psi from the inside, it can handle 15 psi from the outside. Also, the top is flat on this one as well, so it works the same. Only for some models with curved tops would I need to look at the top as well.
In short, it's definitely possible for full vacuum, but I can't legally recommend it.