Short answer: it means exactly what it says and more or less what you fear: from 4th November 2020, the company (Medical Transcription Billing, Corp) has the option of redeeming (= "calling" or buying-back) the Series A Preferred Stock (in whole or in part) at the original issue price of $25 each. This does not necessarily mean the company will redeem any or all of the Preferred Stock – only that it has the option to do so from that date.
This "Preferred Stock" page on Investopedia covers many details of preferred stock, although – as it notes:
Preferred stock comes in a wide variety of forms [...] The features described above are only the more common examples, [...] A company can issue preferred shares under almost any set of terms,
So what that page says is a general overview, and may not always apply to MTBC's preferred stock.
On why a company might buy-back its preferred stock: this starts with the status of preferred stock, which Investopedia describes as:
Preferred shares are equity, but in many ways, they are hybrid assets that lie between stock and bonds.
So in buying preferred stock, you (or the original purchaser if you acquired your stock on a secondary market) is closer to having made a loan to the company than a traditional ("ordinary") stockholder. Redemption under the clause you quoted is, in effect, repaying the loan early. According to Investopedia, a company may consider this:
If shares are callable, the issuer can purchase them back at par value after a set date. If interest rates fall, for example, and the dividend yield does not have to be as high to be attractive, the company may call its shares and issue another series with a lower yield. Shares can continue to trade past their call date if the company does not exercise this option.
Although this includes "and issue another series with a lower yield" I suspect this is one of those "varies by company" things: MTBC does not appear to be under any obligation to issue (or even offer) another series of preferred stock. The repaying of the original $25 "loan" (plus any dividends paid while you held the stock) would cancel all their obligations to you.
For anyone considering buying Preferred Stock (or for you in deciding whether to keep your holding), it is probably worth highlighting the following passages.
Specific to these shares, from the opening page of MTBC's prospectus:
Investing in our Series A Preferred Stock involves significant risks. You should carefully consider the risk factors beginning on page 9 of this prospectus and the risk factors incorporated by reference into this prospectus before purchasing any of the Series A Preferred Stock offered by this prospectus.
and from page 9 of that document:
The Series A Preferred Stock ranks junior to all of our indebtedness and other liabilities.
In the event of our bankruptcy, liquidation, dissolution or winding-up of our affairs, our assets will be available to pay obligations on the Series A Preferred Stock only after all of our indebtedness and other liabilities have been paid.
On a more general note, from the above-referenced Investopedia article:
Preferred stock issuers tend to group near the upper and lower limits of the credit-worthiness spectrum. Some issue preferred shares because regulations prohibit them from taking on any more debt, or because they risk being downgraded.
although it does also note:
On the other hand, several established names like General Electric, Bank of America and Georgia Power issue preferred stock to finance projects.
In short: my interpretation is that – even more so than with "traditional" stocks and shares – buying preferred stock may carry significant risks and is not for the unwary.