Earlier quoted context omitted.
One could just as easily say that you're missing the opposite point: why should policy prevent new people from moving in? In either scenario, policy will disadvantage one group and advantage another. Any policies that aim to give stability to long-term tenants is liable to disadvantage new and shorter-term tenants. There's no natural law dictating that people should be forced to move out, but there's also no natural…
I agree, but I don't think the literal lord of a property should be able to force people to migrate by demanding higher tribute. There should be a rational humane process that isn't driven by simple greed.
Pick a duration upon which to re-evaluate the value of property. Distribute this roughly evenly over all the property everywhere so that it isn't all at once.
When a property's up for evaluation, offer it for 'sale' via a distributed dutch auction as part of a block with similar properties in the same jurisdiction (roughly, zipcodes, or maybe divided up should work).
The block is bid on as a whole, with up to 25% (rounded up) of any of it excluded from the bids (high or low) and with any 'inspection noted defects' (post sale) deducted from the transfer price of the property. Price for a given unit would be proportional to the previously evaluated (by market sale or bid) price of the property among the whole group. Any units not receiving sufficient bidding coverage to provide a fair price should be re-tried with the aim towards the median value of the next group of properties in that area.
The resulting offer is then forwarded to the residents as proof of their new property value and the basis for all taxes upon it. The resident has an option to accept that value anytime within 8 months, for a specified date of no more than 6 months from when they've accepted the offer.