The Middle Age trading practices did help end the feudal system because the trading brought along civility which was required for the new system to work. If the feudal system continued, there was no way for the trading system to function properly and all the participating parties would of resorted to other means.
Yes, medieval trading made the feudal system obsolete. Once it became easier to buy products than to make them, the feudal system was extinct. Supporting huge networks of tenant farmers to make things that were now available for sale elsewhere simple did not make sense. As industrialization began, the agricultural way of life collapsed even further.
Middle Age trading practices ended the feudal system. This is because feudalism was already dying out in a few places due to the increase in trading and barter practices. Getting shelter and clothing just because a person workd for a king began to be somewhat archaic even back then. When people started trading goods like furs and spices more often, it helped to create the trading classes and reduce reliance on royalty.
The feudal system depended wholly on wealth being derived from land. In other words the more land you had the wealthier you were. As industrialization took hold this equation changed and suddenly wealth was derived from the efficiency of factories and logistics chains. Trading practices in and of themselves were not sufficient to cause these changes.
I do not believe Middle Age trading practices ended the feudal system. I believe the feudal system broke apart as governments and higher powers of authority were introduced. I believe the trading practices started before the middle ages and continued on to this day, the routes have simply changed in the time that has passed.