I applaud you for you removing your invasive Bradford pears!

There are several things to consider before planting new trees exactly where you had trees removed and their stumps ground out. Below is a sampling of some of the considerations.

An excellent and simple explanation can be found here:

https://yardandgarden.extension.iastate.edu/faq/can-i-replant-new-tree-same-spot-after-old-tree-removed

Further considerations are below.

https://www.purdue.edu/fnr/extension/question-can-i-plant-grass-over-newly-removed-stump/

An excerpt:

The woody debris material created from stump grinding has a high carbon to nitrogen (C:N) ratio. This reduces nitrogen availability for the new tree or grass. Also, there will be significant settling of the ground below the stump as it decays and loses its structural fiber. The soil should be added to replace the below ground roots and stump. It can take several years to fully decompose the stump unless it was ground very deeply or removed with an excavation machine.

The recommendations are adding soil to the stump area, and a little additional soil mounded to compensate for some decay and the sinking of the area that ensues.

Another:

https://yardandgarden.extension.iastate.edu/how-to/how-remove-tree-stumps

An excerpt:

Promoting Natural Decay

Gardeners can speed up the process of natural decay in several ways. Start by cutting the stump off as low to the ground as possible. Drill several one-inch-wide holes in the stump to increase the amount of area exposed to wood-decaying fungi. The holes should be spaced no more than 12 inches apart and should be at least ten inches deep.

To further promote decay, these holes can be filled with a slow-release fertilizer (about 4 ounces per hole). Most fertilizer formulations will work, but a formulation high in nitrates will promote the quickest decay. Fill the holes with topsoil and cover the stump with soil or sod to help speed up the process even more.

Commercial stump removal formulas/chemicals can also be used as directed on the label. These products tend to simply be a form of fertilizer (often potassium or sodium nitrates), so regular fertilizers can work just as well. Some of the products will also contain a herbicide, such as triclopyr, glyphosate, or imazapyr, to help prevent resprouting. Use these products as directed to prevent damage to nearby plants.

When these methods are applied, the stump can usually be easily broken up and removed with a sharp spade after one to three years.

Another:

https://plant-pest-advisory.rutgers.edu/plant-health-care-phc-concerns-in-the-landscape/

An excerpt:

Typically, when a tree is removed from a property, the owner requests for tree replacement recommendations. However, it is important to remember to grind-up the old tree stump before any new trees are placed near it. There are several root rotting fungi that can become pathogens to living trees that are nearby. Some of the potential pathogens include Xylaria root rot (Dead Man’s Fingers), Ganoderma lucidum(Ganoderma root & butt rot) and Armillaria mellea (Armillaria root rot). With a sizable food source such as a dead stump, these dead wood decay fungi can eventually become primary pathogens and infect live plants. By grinding the stumps, the food source is mostly removed, and these fungi become less of a threat.

Yet one more:

https://web.extension.illinois.edu/askextension/thisQuestion.cfm?ThreadID=15340&catID=199&AskSiteID=