Rule number one in astrology – never make a blanket statement about an aspect or an empty house or anything else you see in a chart. If you do, you’ll be made a fool, eventually.
The 7th house is concerned with partnership and marriage. But having no planets there does not mean you will not marry. You have to look at the chart as a whole.
An empty 7th house may reveal a person who is less interested in partnership than a person with a packed 7th house but this is not always the case. For example if the person has a lot of planets in Libra or Taurus (Venus-ruled signs), they are going to favor relationships no matter where the planets fall in the chart.
There are endless scenarios that see a person with no planets in their 7th house marrying, well and happily so the answer is, no. Having no planets in your 7th house does not mean you will not marry!