PS: after writing this, I re-read the post of yours that I was quoting, and saw that I misinterpreted you. You said “separate path”, and I interpreted that as “seperate goal/shore”. Please read the following in light of “as if you had said” seperate goal/shore" not seperate path.
Well, some Mahāyāna Buddhisms say this, and, as a result, claim that the arhat pracitioner of śrāvakayāna is forever cut-off, severed, and denied, ultimate liberation. This is the ‘seed of bodhi’ theory that Anders talks about on DharmaWheel. The idea being that arhats cut themselves off from the world in a sort of ‘dead end’ state that they remain in forever, forever short of anuttarāsamyaksaṃbodhi (‘nothing-higher-complete-awakening’, a Mahāyāna term for the enlightenment of Śākyamuni Buddha, vs the enlightenment of an arhat or a bodhisattva).
Some Mahāyāna Buddhisms, I am thinking particularly of Tiāntāi (a sect of Chinese Buddhism) and the Gelugpa (a sect of Tibetan Buddhism), argue that highest liberation is not denied to the arhat, and that śrāvakayāna Buddhahood and bodhisattvayāna Buddhahood are one and the same: identical. Their difference being an expedient means to bring more people to Buddhism in general, that the dharma may meet people of all persuasions and karmic conditions. This is all a part of ‘ekayāna’, or ‘ekabuddhayāna’, the ‘one Buddha vehicle’ of Tiāntāi interpretation of the Lotus Sūtra.