Lets call a BUG... A BUG!
taking salvage and delivery missions and then after salvaging get mission message which requires a smaller ship to complete it, why are we being given these missions?
This has nothing to do with a player not paying attention or anything pertaining to choices the player makes.
Its a BUG!
The game "SHOULD" be paying attention to the ship used to accept the mission so that if the destination does get changed, which often happens, the new drop off location is still accessible by that ship. The alternative is getting stuck in a Catch 22 with mission specific cargo that can not be transferred to another ship, but which can also not be delivered to the new delivery location because the original ship can not land at Outposts or similar small pad locations.
Your only recourse in this situation is to bite the bullet and ABANDON the mission.
My advice for the long term would be to ONLY fly ships which can land at ALL stations/outposts in the game. The Python is what I use, and it is about the best multi-role ship you can run at the moment.
Until FD fixes this bug, which keeps resurfacing after many of the updates, that is our reality.
Don't be lead down the Primrose Path by all the misinformation some community members continue to spread about things like this. A bug is a bug!