Yes, if the Church had been more broad minded, the Reformation probably wouldn’t have been necessary.
Actually the reverse is true, given that Renaissance Humanism and before it, Scholastic theology were innovations tolerated in the Roman Catholic Church which to this day are frowned upon amongst the Eastern, Oriental and Syro-Chaldean East Syriac Christians. The Renaissance, interpreted in both the broader context of church history as well as the more narrow categories supplied by the “Magisterial Reformers” (Hus, Luther, Calvin, Cranmer, Zwingli, Melancthon, Boucher, Knox and friends), we see an attempt by those churches driven to the point of schism by pre-Tridentine corruption to roll back the clock and reform the church to a state more authentically representative of the apostolic faith, hence the surprise on the part of the Lutheran theologians when the Ecumenical Patriarch of Constantinople considered certain Lutheran doctrinal positions to be erroneous.
So the reverse is really true: the Reformers sought to turn back the clock; in the process some may have inadvertently developed new theological and liturgiological interpretations, but the intent was clearly a twofold desire to get away from the corruption that was pervasive before the Counter Reformation and to step back into an era not entirely lost to memory when the Roman Church still had an interest in vernacular liturgy and communion in both kinds, among other things. One can clearly see that Rome, which under the rule of primates such as St. Celestine, was the most conservative and absolutely traditional of the Orthodox churches, becoming increasingly open to new theological approaches and changes in liturgical praxis (for instance, Scholastic theology, Anselmian soteriology, the use of Aristotelian logic by the Schoolmen, a proliferation of interesting new models of monasticism which never appeared in the Eastern churches, like canons regular and especially the Mendicant Orders, going to communion in one species, eliminating monotone chanting of the liturgy in the Low Mass, and before that, in the solemn mass, after St. Ambrose introduced it in Milan, the introduction of the Filioque, and
many other things).
I further propose that the more “open minded” churches among the mainline Protestant denominations have in recent years opened themselves up to schism. There have been schisms in the Presbyterian, Anglican/Episcopalian, Lutheran and Congregational denominations, some of which happened before the 1950s (see the break between the CCCC and the other Congregationalist churches a decade before the Reformed-Congregational merger which gave us the modern UCC, and also another more traditional denomination, which now represents the moderate side of the Congregational movement. And of course there is the tragedy of the impending schism in the UMC, which should not happen - the church voted for the Traditional Plan at the last general conference and should focus on implementing that even if it means firing some disobedient clergy and disfellowshipping some parish-level leaders for contumacy (although I suspect that if Methodist conference bishops have the same authority as diocesan and archdiocesan bishops elsewhere, that could be difficult). And the motto of the more liberal UMC parishes was “Open hearts, open minds, open doors,” which sounds lovely, like my former denomination’s famous “Comma” ad campaign, but which is really a clever platitude intended to silence internal dissent to counter-scriptural change and innovation not intended, like that of the Magisterial Reformers, to revert actual and imagined RC innovations, but rather, to engage in such innovation, like the Roman church, in response to external secular pressure.