Was your source indexfungorum? They are frequently out of date for lichens in my experience. I wish I had access to the 2009 paper by Aptroot et al. to understand their reasoning, but I can guarantee molecular work was involved. Their decision to reinstate Herpothallon has been widely accepted in the lichenological community.

Current Name:
Cryptothecia rubrocincta (Ehrenb.) G. Thor, Bryologist 94: 280 (1991)

Synonymy:
Byssus sanguinea Sw., Nova gen. sp. pl.: 148 (1788)
Chiodecton rubrocinctum (Ehrenb.) Nyl., Bot. Ztg. 20: 278 (1862)
Chiodecton sanguineum (Sw.) Vain., Acta Soc. Fauna Flora fenn. 7(no. 2): 143 (1890)
Chiodecton sanguineum (Sw.) Vain., Acta Soc. Fauna Flora fenn. 7(no. 2): 143 (1890) f. sanguineum
Chiodecton sanguineum (Sw.) Vain., Acta Soc. Fauna Flora fenn. 7(no. 2): 143 (1890) var. sanguineum
Corticium rubrocinctum (Ehrenb.) Bres., Annls mycol. 9(3): 272 (1911)
Herpothallon rubrocinctum (Ehrenb.) Aptroot, Lücking & G. Thor, in Aptroot, Thor, Lücking, Elix & Chaves, Biblthca Lichenol. 99: 61 (2009)
Herpothallon sanguineum (Sw.) Tobler, Flora, Jena 31: 447 (1937)
Herpothallon sanguineum (Sw.) Tobler, Flora, Jena 31: 447 (1937) f. sanguineum
Hypochnus rubrocinctus Ehrenb., in Nees von Esenbeck (ed.), Horae Phys. Berol.: 84, tab. 17, fig. 3 (1820)
Hypochnus sanguineus (Sw.) Kuntze, Revis. gen. pl. (Leipzig) 3(2): 486 (1898)
Thelephora sanguinea Sw., Fl. Ind. Occid. 3: 1937 (1806)