No, landlords would NOT be poorer, they're taking in exactly the same as before devaluation. Devaluation directly effects ONLY imports (more expensive) and exports (cheaper): it effects the local economy only based on how much it depends on each.
Government declares that the arbitrary denominators of value now buy half the number of a different arbitrary denominators of value they did previously.
Because I am a locovore Luddite (for the sake of the argument), everything I buy is made in the country, with materials produced in the country.
How does the devaluation effect me?