After large delete on table - Table Fragmentation ?

Hello, App team is planning on deleting millions or rows in a large table.

Table has Foreign Keys/Constraints/Indexes but no Nonclustered index.

After they disable Foreign Keys/Constraints is there such thing as Table Fragmentation?  (Aside ofIndex Fragmentation.)

If yes how should Table Fragmentation be addressed?

Also would Index rebuild or reorg should be done as well after large deletes?

Thanks in advance.