Source of Sloka

The shloka that has surfaced and popularised in the recent times raises many critical questions.

अवतीर्णश्च कालट्यां केदारेऽन्तर्हितश्च यः ।

चतुष्पीठप्रतिष्ठाता जयताच्छङकरो गुरुः ॥

What is the pramanam or source of this shloka? It appears to be a recent composition.

Hence the author of this sloka should step forward to clarify on what basis it was composed and why it has been intentionally prioritized over the traditional gurumahima slokas.