Is the result the same regardless of who you choose to confess your love for if you go with Ryuji on the October 26th post festival party?
This falls into the same category as the Hawaii date, in that this doesn't lock in a romance target. Romance seems to be soley dictated by the quesiton at S.L. Level 9.
A good barometer of this seems to be "Are all possible romance targets an option here?" as the only options given here are party members, some are dudes (non-romancable in p5), and it includes morgana whose social link is progress based.
At most it'll likely raise some social link points, but it's unlikely due to Morgana being an option.