(a) The fact that none of the well-educated native speakers here knows what it is should suggest that it is something to avoid, or at least not bother about. (b) If I was being generous, I would say that someone invented the word to describe a process that is unfamiliar in the west. (c) If I was less generous, and more honest, I would say that it's more likely that the word was in fact invented as a form of euphemistic, or whitewashing propaganda.

I have never heard of the word before, so I Googled it. Look at the sentences below, which are from http://journals.sagepub.com/doi/abs/10.1177/0920203X17736508?journalCode=cina "This article discusses state-led heritagization processes in Beichuan and Wenchuan Counties, two Qiang ethnic minority areas severely affected by the 2008 Wenchuan earthquake (China). Certain destroyed landscapes were preserved and turned into earthquake relic sites." This tells me that "heritagization" is the process of incorporating something of cultural value into the national or cultural heritage of a nation or people. The above example discussed the heritagization of earthquake ruins in China i.e. preserving them as part of the heritage of China for future generations.

To be honest: I don't think you will ever need this word in English, and if you do, you should try to find a simpler way to say it. I had to look up its meaning, myself.

Here it is Heritagization here must be seen as a case of re-telling from a new perspective; a process used to adapt to new lives in new lands. From the immigrant’s view, being a stranger in a new, sometimes hostile land required not only survival skills and in-group supports in order to get on with living, but also cultural changes and new symbolic ideas about life. In the old country, ideas about home, identity, behaviour and values would be rooted in place, historical connections, culture, and institutions.

You will have to provide a reference or context.