When the SEC filing is made, we'll get to see how the deal is structured. The $20 billion from TD Securities becomes a debt obligation of the combined company. There's a tax break in equity to debt conversion, and a second tax break for carried interest. [2] There may be a preferred stock deal or debt refinancing so that TD gets their $20 billion back. Usually, the private equity firm exits within a few years.
[1] https://pubs.aeaweb.org/doi/pdfplus/10.1257/jep.23.1.121
[2] https://www.pgpf.org/article/what-is-the-carried-interest-lo...
This is a public-to-public merger. Some mergers and acquisitions are financed with debt. That does not make them leveraged buyouts.
LBOs are private equity deals in which there's no issuance of public stock. The equity portion is, well, private equity.
Source: I've advised over 100+ clients on billions worth of M&A and LBO deals in my time as an investment banker in New York.
A third of the deal is financed with debt. A fifth is financed with cash. The bulk—fifty percent—is being financed with equity. An LBO would see debt and a thin tranche of cash finance the bulk of the acquisition.
The one I was most familiar with was the Discovery “acquisition” of Warner Brothers. Though apparently that’s a little complicated because AT&T was divesting itself of Warner.