Here's an excerpt froma subset of the table of contents, with my own annotation about which sections are expository:
2 Global symmetry
2.1 Splittability — expository. This section coins the name "splittable symmetry," which is an ancient-but-important concept that really needed a good name.
2.2 Unsplittable theories and continuous symmetries without currents — expository
2.3 Background gauge fields — expository
2.4 ’t Hooft anomalies — expository
2.5 ABJ anomalies and splittability — expository. You can read about 't Hooft loops in this section.
2.6 Towards a classification of ’t Hooft anomalies — expository
3 Gauge symmetry
3.1 Definitions — expository. Don't be fooled by this section's boring name. This section re-introduces key concepts like Wilson loops, even though loops/lines were already used in the preceding sections.
3.2 Hamiltonian lattice gauge theory for general compact groups — expository
3.3 Phases of gauge theory — expository
3.4 Comments on the topology of the gauge group — expository
3.5 Mixing of gauge and global symmetries — expository
4 Symmetries in holography - expository
5 Completeness of gauge representations - expository
6 Compactness - expository
7 Spacetime symmetries - expository
8 $p$-form symmetries - expository. This is why the paper is relevant to the question.
8.1 $p$-form global symmetries - expository
8.2 $p$-form gauge symmetries - expository
2 Global symmetry
2.1 Splittability — expository. This section coins the name "splittable symmetry," which is an ancient-but-important concept that really needed a good name.
2.2 Unsplittable theories and continuous symmetries without currents — expository
2.3 Background gauge fields — expository
2.4 ’t Hooft anomalies — expository
2.5 ABJ anomalies and splittability — expository. You can read about 't Hooft loops in this section.
2.6 Towards a classification of ’t Hooft anomalies — expository
3 Gauge symmetry
3.1 Definitions — expository. Don't be fooled by this section's boring name. This section re-introduces key concepts like Wilson loops, even though loops/lines were already used in the preceding sections.
3.2 Hamiltonian lattice gauge theory for general compact groups — expository
3.3 Phases of gauge theory — expository
3.4 Comments on the topology of the gauge group — expository
3.5 Mixing of gauge and global symmetries — expository
7 Spacetime symmetries - expository
8 $p$-form symmetries - expository. This is why the paper is relevant to the question.
8.1 $p$-form global symmetries - expository
8.2 $p$-form gauge symmetries - expository