If you want to play rugby then yes pre-season training will be great. If you don't want to play again then the jury is out.
It may tempt you to play again, or be a substitute on the odd occasion which has increased injury risks.
It may be a good motivation and lots of fun so it has its merits.
Shouldn't be any major knocks pre-season if done right - it should be fitness and skills based. No need to increase the battering players get over the season. Can never rule out a twist or a bang though.
You will get more sport specific training through running, cycling and swimming.
At the start I found continuos running hard rather than the stop/start of rugby.
I'll leave you with just one question?
Are you an ex-rugby player?
Drop the ex- for the alternative. It is a tough question to answer. My decision was made the third time I displaced 3-vertabrae in my back in one season.
I work in a job where I don't have easy access to toilets, and have to try to plan accordingly. However I have been that close to having an accident in the past that I've leapt over farm fences, ripping my pants in the process, to get to an area of relative cover to get the job done.
Did you just leave the train idling on the tracks?