The Bunker Group
Yes, without that none of those three will want to venture on building something with Antonov. Destruction of Antonov facilities in Hostomel, Svyatoshn and Kharkiv practically destroy Antonov manufacturing capabilities within Ukraine. Only two others aircraft manufacturing that experience building Antonov aircraft, and both in Uzbekistan (Tashkent) and Russia (Voronezh). Something I don't think will be workable for Antonov even before the war.Even then, LM, Boeing, and Airbus would want their respective governments to subsidize any investment.
So either Antonov become just a design bureau (which is basically how it is started) and working with Partner that have manufacturing facilities, or find some partner that want to finance rebuilding the facilities. Potentially the former one that can be realistically happen.
This off course has to be Government back, cause commercially not enough incentive to revive Antonov design by pure commercial foreign investors. Their design under current market conditions just not competitive enough commercially.