The name 红宝书 is popular in mainland China. Chinese from Taiwan or other se asian community just call it 小红书 or 毛語錄
Guess what
1. As you mentioned, Xiaohongshu, is the same name of Quotations from Chairman Mao Tse-tung
2. The CEO of Xiaohongshu has the surname Mao
3. The headquarters of Xiaohongshu is located near the site of the First National Congress of CPC
obviously, this is part of CPC's conspiracy