As GAMCO Investors owns a significant stake in TDS, the letter expressing concerns about the company's performance and the possibility of nominating directors at the next shareholder meeting shows that GAMCO is actively involved in TDS's corporate governance. However, the short-term impact on GAMI's stock price is uncertain, as the outcome of the shareholder meeting and the potential changes in TDS's management are yet to be seen.

The letter from GAMCO Investors, a significant shareholder, expressing concerns about TDS's performance and the possibility of nominating directors at the next shareholder meeting may negatively impact TDS's stock price in the short term. Investors may perceive this as a sign of potential management changes and uncertainty, which could lead to a decrease in the stock price.