Quite opposite. The money of few American tourists which will come to Poland because of strong USD are probably smaller that money lost by Polish tourists which will choose Greece instead of Baltic sea.
Just look here:
A study conducted in 2013 evaluated the average expenditure of tourists visiting Poland at 401 USD per person and 76 USD per day of stay (weighted averages). Comparison of the data obtained with those evaluated on the year 2012, indicates a slight decrease of average expenses per person (approx. 0.7%) and daily expenses (by about 2%); in both cases it refers to the weighted average.
Disturbing in this case is the fact that the downward trend, albeit small, remains steady since the fourth quarter of 2012.
There were 300,000 American tourists in Poland in 2013 and 5,300,000 German. American tourists are not important for the industry, except if few times more will come now.