We are looking at alternates for the AD5324 (mainly for cost reduction), and it seems that the AD5624 is a good candidate. Would the AD5624 be considered a very close replacement for the AD5324? The current DAC is used in a low speed correction loop with an external +5V reference, running at approximately 125kHz sample/update rate. Among the differences I see are pin mapping, and 24-bit DIN vs 16-bit DIN.
You are correct that the AD5624 is a good candidate for the AD5324. If you wish to see more viable candidates, you may want to use the parametric search available at the website.