The various Vedantic sects are divided into those that consider Brahman to be different from Jiva (dualists) and those that consider them to be identical (non-dualists). Most of these schools acknowledge that people following other schools can attain high spiritual states. What nondualists are not sure of is whether dualists must have the experience of Nirvana. Similarly dualists are not sure if nondualists can experience the intense bliss enjoyed by the dualists.
Mahima: "I have a question to ask sir. A lover of God needs Nirvana
(total annihilation of ego -- the ideal of the jnani) some time or
other, doesn't he?
Master: "It can't be said that bhaktas need Nirvana. According
to some schools there is an eternal Krishna and there are His eternal
devotees. Krishna is spirit embodied, and His abode is also spirit
embodied. Krishna is eternal and His devotees are also eternal."
The Gospel of Sri Ramakrishna, Chapter 41, At Ram's House