I previously used "conservative" to mean an ideology that seeks to maintain appearances while leaving private life to the individual conscience. All authentic Islamic schools follow this pattern. Wahhabism is a new ideology that seeks to bring Arab society in line with how it was structured in the lifetime of Muhammad. (As the Wahhabists understand it, which is historically dubious.)
To be consistent with my previous usage, I'd have to classify Wahhabists as extreme reactionaries. This is also consistent with Islamic scholarship. When they first appeared, Wahhabists were denounced as heretics by the consensus of Islamic scholars.
Traditionally, Islam has never understood itself as seeking to preserve one culture or another. Its purpose is to worship God and create a just society as Islam understands it: feed the poor, care for orphans, prevent female babies from being abandoned, prevent slaves and animals from being overly mistreated, etc. For taking good care of the world, they expected its creator to reward them in extremely sensual ways.
IIRC one of the most influential scholars, al-Ghazali, suggested that the purpose of Islamic law is to protect the 5 components of well-being: religion, life, intellect, offspring and property.
In this context, even the understanding of "religion" is more universal than you might expect. Islamic theology is very different from Christianity in that you don't have to follow Muhammad's revelations to be a "muslim", i.e. submit to God. According to Islamic scholarship, God created humanity with an innate disposition to believe in him:
https://en.wikipedia.org/wiki/Fitra Apparently, anyone who doesn't reject the stirrings in one's own soul to worship God and uphold justice is a true believer and will be rewarded. There is a medieval novel that spells out the consequences of this understanding:
https://en.wikipedia.org/wiki/Hayy_ibn_Yaqdhan
Neither in the words of the Quran nor in traditional scholarship does Islam have anything to do with a reactionary preservation of Arab culture as attempted by the Wahhabists.