I think it’ll just be for Euros - the selection documents on BG’s site say the selection meeting for Euros is on 14th March, but for Junior Worlds is on 27th February, so too early for this.
Even though the selection will be made after this trial, gymnasts selected for Euros will be required to compete at the British Championships (which finish 16 days before Euros starts).
Also note that due to the new qualification system for Worlds, the format of these Euros has changed. Qualifications will be in a 5-4-3 team format with medals up for grabs, so GB may well focus on team gold even though they don’t need to worry about Worlds qualification.