Plasma accelerators generate accelerating fields that are up to 1,000 times higher than fundamentally possible in RF accelerators. They therefore offer a promising alternative path to the high-energy frontier. In 2012 the European Strategy Preparatory Group received for the first time detailed input about the prospects and promise of plasma accelerators, a 15 page report provided by the EU-funded European Network for Novel Accelerators (EuroNNAc). The network published a 31 page report on a European strategy for plasma accelerators in 2017. Here we provide a short update on the prospect of plasma accelerators for high energy physics. We propose that the next European strategy for particle physics should explicitly list ultra-high gradient plasma acceleration and, if possible, its supporting international projects as essential R&D towards a compact alternative for future colliders.