Analysis of information sources in references of the Wikipedia article "Reforms of Russian orthography" in English language version.
... the Russian spelling reforms of 1917–1918 were based on proposals drawn up by an imperial commission thirteen years earlier, slightly watered down. However, because they were implemented at time of great social upheaval, these reforms divided Russian literati into two camps. Adherence to the old orthography became a mark of adherence to pre-revolutionary values, and some émigré presses continued to employ the pre-Soviet conventions until the 1970s.
{{cite journal}}: CS1 maint: bot: original URL status unknown (link) Вознесся comes from Church Slavonic and was in Pushkin's times presumably (but not surely) pronounced with е, see: П. Я. Черных (1949). "Из наблюдений над языком стихотворения Пушкина «Памятник»". Русский язык в школе (3): 33–37.... the Russian spelling reforms of 1917–1918 were based on proposals drawn up by an imperial commission thirteen years earlier, slightly watered down. However, because they were implemented at time of great social upheaval, these reforms divided Russian literati into two camps. Adherence to the old orthography became a mark of adherence to pre-revolutionary values, and some émigré presses continued to employ the pre-Soviet conventions until the 1970s.
{{cite journal}}: CS1 maint: bot: original URL status unknown (link) Вознесся comes from Church Slavonic and was in Pushkin's times presumably (but not surely) pronounced with е, see: П. Я. Черных (1949). "Из наблюдений над языком стихотворения Пушкина «Памятник»". Русский язык в школе (3): 33–37.