Current advancements within the WiFi domain, such as network densification, traffic offloading, and IoT support, pave the way for increased user and operator satisfaction with future (5G and beyond) network deployments. However, without seamless coexistence of novel and legacy WiFi devices as well as between heterogeneous WiFi networks, the goal of ubiquitous and effortless wireless access may be delayed. In this article, we identify several future WiFi use cases based on current trends in the research community as well as developments within IEEE 802.11 and analyze the functionalities required in these use cases, taking into consideration two important aspects: coexistence between new and legacy WiFi devices, and inter-network interference. Through our research we show that, despite several identified shortcomings and open issues, WiFi will definitely be a crucial component of future network deployments.