Who gets the accumulated preferred stock late dividend payments?

Your understanding is basically correct. But keep in mind that a company can stop preferred dividend payments at any time for any reason (even if they're profitable), as long as they're not paying a dividend on a lower ranking security which would be their common shares. All the nuance is spelled out in the prospectus, but in most/all cases, if Company XYZ pays any dividend at all on their common shares, then they MUST also pay the FULL agreed upon preferred dividend and can not cut it by a single penny. So if XYZ is having money issues and cuts their common share dividend from 50 cents a quarter to only 1 cent a quarter, they cannot cut their preferred dividend at all and must continue to pay it. However if XYZ cuts their common share dividend to 0 cents (or never payed a common dividend to begin with), then they can cut their preferred dividend by any amount, though it would typically be cut to 0.

Now if the dividend was cut or (most likely) eliminated on preferred shares that are cumulative, the missed payments begin to accrue on their books and generally need to be paid in full before a single dividend payment can be made on their lower ranking common shares. If they never intend to pay a dividend on their common shares, then they would never need to resume payments on their preferred shares, though they would risk being locked out of the preferred market to ever issue new shares. A recent example would be HOV which I don't believe ever paid a dividend on their common shares. They ran into financial trouble and stopped payment on their preferred shares around ~2008. Even though they still don't pay a common dividend, they decided to resume payments on their preferred shares in 2022 after many years of recovery. The rationale (paraphrasing) was that even though they weren't required to, their increasing financial stability allowed them to resume preferred dividends, and they wanted to do right by their investors. So sometimes you get lucky, but interestingly the HOVNP preferred shares are NOT cumulative, so they were not required to pay back 14 years of missed dividends--if they had been then maybe they wouldn't have been so generous.

Finally, to answer your question, only the current holder of the preferred shares would be entitled to missed payments if they're ever paid back. So if you sold them, you would not receive any missed payments.