The traditional position is that unless the person who commits suicide is of unsound mind and not fully responsible for his decision, or unless death takes a while, giving the person time to repent, then it is a mortal sin with no chance to confess and repent.
In other words, suicide is a one-way ticket to Hell. That is why, traditionally, suicides were not allowed to be buried in consecrated ground. God, of course, can do whatever He wishes, and presumably can offer a suicide a last-second chance to repent. But it would be extremely foolish to rely on that possibility.
I do think it is the duty of the Bishops to point that out, in the hope of dissuading Catholics from committing suicide or agreeing to euthanasia. After all, the most important duty of the Bishops is to save souls.
Excellent points.