Ejection from long time dwelling

Good Day, I live in a family compound in Guadalupe. I have lived there for 23 years with other members of the extended family. A cousin of the family who had a certificte of registration for the land moved to the US many years ago where she had two sons. She died intestate some years ago. In June this year one of the sons came to Cebu and said he was selling the compound to a Developer The compound houses 12 families who are all related. The Son has no title for the land. His mother had no title for the land. Some family members even have a small business on the outside of the compound. The entire compound was told to leave by January. Just this week a letter from an attorney arrived stating that if all did not leave within fifteen days then Court action would be started for ejection.
Can this happen legally and does the son have to provide alternative housing or compensation before ejection ?