Yes, definitely. When I was active in the Esperanto movement in the 1990s and early millennium, a huge amount of the Eastern Europeans who attended congresses or hosted foreigners through the movement's hospitality-exchange system had little or no English skills. They had learned Russian, German, or French in school, not English. This was also the case for some Esperantists from francophone nations of Africa; some of those countries were historically so fixated on French as the international language that English teaching in schools took off only recently.
Nowadays the younger generations of Esperantists are likely to speak English, but to judge from photos, the crowd attending the main annual Esperanto congress is generally pretty geriatric, so that older generation without English is still commonly met.